70,000 watt mobile setup [Archive]

WA2ZDY

03-10-2004, 09:10 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (N2KIN @ Mar. 10 2004,01:09)</td></tr><tr><td id="QUOTE">Too much free time and beeeeer... #:)

brainwash them and "convert" them into real hams #:p[/QUOTE]<span id='postcolor'>
No, those are folks with no sense and absolutely ZERO respect for the law. We don't want them in our fraternity. They would most certainly only continue their lawless ways. And how would that benefit ham radio? Not at all.

And as for 70kw . . . I've been in broadcast stations. I'm not sure how one would get the equipment for 70kw out in the back of a truck. My own opinion is getting that much power even from all those alternators would be tough. (Yes, I know, I've seen posts here confirming it can be done. I still have my doubts.)

Ah well, whatever. There's weirdos in every group. I dated a lady once who was a ham and so were her brothers and father. One day Dad fired up the Henry 4K and showed me 3800w out on the Bird. I questioned him about it and his quote was: "Can I help it if my dummy load is six elements at 60 feet?"

w8amd

03-10-2004, 09:40 AM

There are no brain cells left to fry in the head of anyone who would key up anything near half that power in a mobile installation along with all who are silly enough to sit by and watch.

This is your brain on RF http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif
Get the picture.

W1RFI

03-10-2004, 12:35 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KC8QMU @ Mar. 09 2004,01:31)</td></tr><tr><td id="QUOTE">Yeah, keying 70kW next to your head can't be good, at any frequency.

The sad thing is, they probably have more know-how than most of the hams these days. http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif[/QUOTE]<span id='postcolor'>
Not if they key down 70,000 watts right next to their heads...

For that matter, not if they think they are generating 70,000 watts from those setups. At 12 volts, that would require about 8000 amps, giving them 70% efficiency. Even if they were to run those alternators at full voltage, the best they can probably manage is about 50 volts,which would need about 2000 amps. I sure didn't see any wires big enough to handle that kind of current in any of those photos. If these guys believe they are managing that kind of power in the installations I saw, I don't think that they are quite as bright as you think they are.

73,
Ed Hare, W1RFI

ki4bgo

03-10-2004, 12:40 PM

That set-up looks like "just the cure" for BPL! http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

N8YV

03-10-2004, 02:03 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KC8QMU @ Mar. 10 2004,02:31)</td></tr><tr><td id="QUOTE">The sad thing is, they probably have more know-how than most of the hams these days. http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif[/QUOTE]<span id='postcolor'>
Define "know-how". #

I'd bet these clowns have less than one-third of whatever RF they are radiating, that is actually being used on their frequency. #The rest is just harmonics and spurious garbage.

I'd also bet these "studs" have sharply-reduced sperm counts, after their nads are exposed a few times to that RF, not to mention their obvious lack of brain cells.

What a waste of time and money!

(And to think these people might actually have the right to vote)---Scary!!

WA3KYY

03-10-2004, 02:19 PM

Maybe these folks should hold their next shoot-out in Cincinatti. http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

ai4ep

03-10-2004, 02:28 PM

http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif ....notice there arent any FORD vehicles in the pictures ( another thread )....really you COULD notice several things just by the pictures, but I dont feel it is necessary for ME to point out what YOU can see just by looking real close at the pictures....be your own Columbo !!.... http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif ( pictures are worth at least 1000 words EACH )

w3bny

03-10-2004, 02:32 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">notice there arent any FORD vehicles in the pictures [/QUOTE]<span id='postcolor'>

Yeah cuz Ford owners aint that friggin stoopit! http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

03-10-2004, 03:17 PM

I just figured it was 'cause Fords broke down before they got there!

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

WA7KKP

03-10-2004, 05:19 PM

Can I laugh my fanny off right now, or do I have to wait for the polls to close???

Assuming everything was about 100% efficient, you would need 100 hp to create 70KW, and with normal efficiencies, I would guess you would need 200 hp. With taxable HP from an engine usually in the 20-50 HP range, I'd say that engine would have to be pretty good sized to do that. And the gas tank would have to be large enough to last more than a couple minutes.

I remember years ago of a CBer braggin about a 4 KW AM station, using a "linear" of course. He said it ran off 120VAC. I laughed then and there, because I knew to get that kind of power you needed three phase AC for the plate supply alone.

This proves you only need a fraction of a brain to be a CBer.

Gary Hildebrand WA7KKP

K9STH

03-10-2004, 06:47 PM

KKP:

The Polls closed in Texas at 7:00 PM last night! I know, I am the election judge of Precincts 48 and 55, Collin County, Texas! They opened at 7:00 AM.

YV:

Think a moment. If the "shoot out" participants have a reduced sperm count, and if they participate in a number of these activities, then pretty soon their reproduction abilities should be greatly reduced if not eliminated. Now, although this wouldn't do a whole lot of good for this generation, at least the genetic mindset would be greatly reduced, if not completely eliminated for the next generation.

Glen, K9STH

K6WXA

03-10-2004, 07:18 PM

Boils down to this plain and simple...

Friggin' Stupid

03-10-2004, 07:19 PM

Now come on for a minute.

Seriously, somebody needs to go to these things and educate them on the dangers of RF overexposure.

I'm sure a lot of these guys just don't KNOW how much damage they're doing to themselves and others.

Whaddya looking at me for? I'm not stepping foot around those maniacs!

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

ky5u

03-10-2004, 07:59 PM

Another "urban legend". # You MIGHT be able to do 7KW AM. #Like Ed and the other guy talking about horsepower, there weren't wires big enuf, motor, transformer, batteries enough to support the claim. #I have been seen the 50KW transmitters for WWL 870AM as well as 100K jobs for FM and what is required running them on 440 and 220 AC.

In colloquial terms, Horsehockey!

W5HTW

03-10-2004, 09:37 PM

Well, I don't doubt the CBers THINK they are running 70KW. Which is like 700 pounds, right? Or about "70 little dots over S9 on the meter." Or "It pegged my meter, so it's gotta be way up there."

No, please no, don't even mention ham radio to these idiots! As someone said, if they came to ham radio, they'd bring their operating (??) style and habits with them. We already have the proof of that, so why push it to ever worse limits?! In fact, if one of them mentioned ham radio I'd tell him it was all moved to 27 mhz a couple of years ago. Why on earth would we want to recruit more CBers into this hobby? Geez!

I think these CBers have the same imagination that brought us the "power mike" which was supposed to "talk across the country if you turn it up" and which has (very unfortunately) found its way into ham radio. Same folks who think the coax should be 9 feet long. And when talking to someone and he's weak, they say "Turn your volume up a bit so I can hear you better."

Leave 'em where they are!!

ed

ai4ep

03-10-2004, 09:58 PM

http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif ...are you sure it was a " shoot out " or a N C I weekly meeting ? ( some times they may blend the 2 events together ) ...ya neva know !! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

WF7I

03-10-2004, 10:13 PM

This sounds a lot like the urban legend I heard about the Phoenix CBer who, in the late 70s or early 80s supposedly put so much power from his "leeeeenear" into his moonraker antenna, that the antenna melted down onto his rooftop while he was talking. So people hearing his signal noticed a steady decline. I think there is a second part of the story that says his roof caught fire. Now I don't remember the exact power that was stated, but I feel it was above 10kW for sure.

n0ov

03-10-2004, 10:17 PM

Ok, I'll bite

What does a CBer need with 70K mobile setup?

Do they want to be able to jump start a car without the cables? Or maybe cook that chicken on their antenna on the way home http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

N0KLT

03-10-2004, 10:20 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ki4dya @ Mar. 10 2004,13:19)</td></tr><tr><td id="QUOTE">Now come on for a minute.

Seriously, somebody needs to go to these things and educate them on the dangers of RF overexposure.

I'm sure a lot of these guys just don't KNOW how much damage they're doing to themselves and others.

Whaddya looking at me for? I'm not stepping foot around those maniacs!

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif[/QUOTE]<span id='postcolor'>
Educate them my a**, it's called applied Darwinism, leave the dummies alone and they will clean out their own end of the gene pool. Just don't get anywhere close to them while they are doing it. Think of a 70kw cb as a slow acting chlorine for the gene pool. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

73

Gary NØKLT

W1RFI

03-10-2004, 10:21 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ki4dya @ Mar. 09 2004,13:19)</td></tr><tr><td id="QUOTE">Seriously, somebody needs to go to these things and educate them on the dangers of RF overexposure.#[/QUOTE]<span id='postcolor'>
Let's stick with the untenable premise that they are managing to generate 70,000 watts of RF with those puny little generators.

If they are using 70,000 watts on 27 MHz and have an antenna gain of 1 dBi (typical mobile whip), if the area of human exposure were to be 5 feet from the antenna, an estimate of the RF safety aspects of that operation is:

E field: 1707 V/m
Permitted E field: 30.7 V/m
The field would be 34.9 dB higher than permitted.

This is a power density of 773 millwatts flowing through each square cm. #

The RF safety limits are based on a specific absorbtion rate of 80 milliwatts/kg of body mass (we would absorb about 6 watts across our entire body from a "legal" exposure). #A level 34.9 dB higher than that would mean that a nearby person was absorbing 247.2 watts per kilogram. A 75 kilogram human would absorb 18,541 watts from that field.

Do any of you know enough about things thermal calculations to estimate how long it would take to cook a human with 18,541 watts 100% coupled into that person? I look at what happens to a kilogram of food in my microwave oven where I have about 500 watts inefficiently coupled and it is an effect greater than I would like to see exposing me. Now, admittedly, the near-field effects will result in less than 18,541 watts being coupled into an nearby person, but even at 10% coupling efficiency, I don't want to be an 1800 watt thermal source or sink. Admittedly, I would probably cook rather slowly, but that would only make the process even less enjoyable.

Anyone still think they are generating 70,000 watts, or is this one pretty much settled?

For that matter, have we decided whether they are smarter than most hams or not? :-)

73,
Ed Hare, W1RFI

n0ov

03-10-2004, 10:23 PM

kind of makes you happy the don't have access to 23cm http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

KC8QMU

03-10-2004, 10:31 PM

By "know-how" I mean ingenuity and maybe the interest in building something. #When I see the number of hams paying big bucks for a simple pre-assembled dipole I can't cut on anyone that turns a vehicle into a generator.

It may do 70kW (PEP), just not for long. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

But yeah, common sense isn't so common. #For all the work and money they spend to blow each other off of channel 6 I don't understand why they wouldn't get involved with REAL radio and actually use it for a more civil purpose.

http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif

ky5u

03-10-2004, 11:08 PM

If it would fry you in seconds, the obvious trick is to get more CBers to witness the demonstration.

03-10-2004, 11:41 PM

Gee...I wonder...Would the Amateur radio equivalent be a bunch of Extras, running 1500 watts (or more-must be lots of old commercial henrys floating around) "Just because they can" with the winner being the one who can hog the frequency the farthest on groundwave? With maybe a sub contest of who hogs the frequency in the farthest DX location?
http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

ai4ep

03-11-2004, 12:49 AM

http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif ...lets see...maybe they needed 70,000 watts of stray RF to cook the chickens, steaks, bar b q , etc to FEED all those folks in those pictures whose faces are all blurred from the stray rf floating around !!

K8YS

03-11-2004, 01:10 AM

AFTER I stopped laughing, I got to thinking about all that RF, that close to the operator....

You know what I call this....

the filter system on the GENE POOL.

K4KWH

03-11-2004, 01:26 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (WA3KYY @ Mar. 10 2004,07:19)</td></tr><tr><td id="QUOTE">Maybe these folks should hold their next shoot-out in Cincinatti. #http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif[/QUOTE]<span id='postcolor'>
I think they DO have one in Cincinnati at some point during the year.

Whatever they put out, they call them "bird" watts. #LOL!

......................as in COO COO!

K9STH

03-11-2004, 02:31 AM

WF7I:

Back in the late 1960s, to test the autotune capabilities of one of the 20 KW Collins Radio amplifiers that were being built for the United States military, one was hooked up to a "long wire" about 100 feet long that was laying on the concrete floor of one of the buildings at the "new" corporate headquarters here in Richardson, Texas. The exciter was locked down in the CW position somewhere around 20 MHz and the amplifier was allowed to "do its thing".

The wire started arcing and burning at the end. As the wire burned, it got shorter and shorter and shorter. It was less than 2 feet long when the amplifier finally "shut down" because the autotune circuit could no longer handle the load.

Also, when the old Collins Radio antenna group was building the 10 dBd log-periodic antennas that covered 3 to 30 MHz, they used a KWM-2A operating on SSB and one of the 10 KW military amplifiers. Since the work was being done for the military, and since the radio operators all had commercial radio telephone licenses, they could test these antenna anywhere within the actual frequency range.

One frequency that always got used for several test transmissions was the Class "D" Citizen's Radio Service channel 19. Since these 10 KW amplifiers were 10,000 watts output, and with the 10 dBd antenna gain, that meant an effective radiated power of 100,000 watts. Of course when they transmitted on channel 19, every other transmission ceased. Then, a few seconds later, the comments like "WHAT was that" started! Next all sorts of stations would start calling "whatever" made all the receivers go "belly up".

Then, the technicians would put out a few more "test" transmissions and then sit back and "laugh" at all of the "traffic" that the test transmissions had generated. The comments from the "CBers" would go on for hours.

Glen, K9STH

w3sy

03-11-2004, 03:07 AM

Q: What do you call 100,000 watts ERP on Chicken Band Channel 19?

A: QRP.

Haw.
Out.

AB8RU

03-11-2004, 03:27 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (WA2ZDY @ Mar. 10 2004,07:10)</td></tr><tr><td id="QUOTE">http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif9--></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (N2KIN @ Mar. 10 2004,01http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif9)</td></tr><tr><td id="QUOTE">Too much free time and beeeeer... #http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

brainwash them and "convert" them into real hams #http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif[/QUOTE]<span id='postcolor'>
No, those are folks with no sense and absolutely ZERO respect for the law. #We don't want them in our fraternity. #They would most certainly only continue their lawless ways. #And how would that benefit ham radio? #Not at all.

And as for 70kw . . . # I've been in broadcast stations. #I'm not sure how one would get the equipment for 70kw out in the back of a truck. #My own opinion is getting that much power even from all those alternators would be tough. #(Yes, I know, I've seen posts #here confirming it can be done. #I still have my doubts.)

Ah well, whatever. #There's weirdos in every group. #I dated a lady once who was a ham and so were her brothers and father. #One day Dad fired up the Henry 4K and showed me 3800w out on the Bird. #I questioned him about it and his quote was: #"Can I help it if my dummy load is six elements at 60 feet?"[/QUOTE]<span id='postcolor'>
These people I would agree are real story stretchers, have no clue to what electronics theory is, and the Broadcast Stations uses stuff that literally is big alright, they are far out in the left feild and anyone who is not familiar with broadcast stuff ask any Broadcast Engineer the ERP ( Effective Radiated Power ) just a AM or an FM Broadcast Station Puts out.

I am just going thru my seond time on the CRO Certification book and also got a look at a flier for a Broadcast Antenna, the guy on the tower assembling an antenna that takes alot of power much more than a 2 KW Amplifier would.

also Never believe these Urban Ledgens that these 11 Meter CB operators post on the web is pure URBAN LEDGEND thats why we that are into this feild know better.

Just a real Laugh http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

03-11-2004, 03:30 AM

I saw that site and marveled at the never-ending 'ego boost' that these types of folks like to get when they use those claims like '70KW' output from their 'mohhh-byles'! http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

They don't know any better and those that do keep their yaps shut, most of the time.

To give you an idea of what's required to generate 10KW of RF on HF (from a mobile environment) without cooking the gear....

The 'bestest' demonstration of a high power mobile was a piece of HF military gear that I had the pleasure of observing in a test situation many years ago.

Seems the Customer wanted a MOBILE HF transmitter with REMOTE operation. (Note.. remote operation! VERY important to the story)... so they could have solid comms almost anywhere they wanted. They wanted 10KW PEP, 5KW DC output power. Modes desired were SSB and CW/RTTY. They spec'd output at being able to be produced into max 6:1 mismatch, without time limitations, minimum 5KW output for RTTY and 10KW PEP for SSB, 10KW for CW.

Requirements were 12VDC feed with appropriate voltage/current inverters to generate necessary DC voltages for fils, grid, plate, screen, etc.

<I won't mention WHICH Customer, but suffice it to say they had a lot of bux floating around in cubbyholes that weren't labeled with the accurate names of what they were REALLY for! HI! >

Anyway.. the contractor built a 4 tube xmtr using 4CX10000 tubes. Class C for CW/RTTY, Class AB1 for SSB. Autotune antenna matching, input voltage foldback for protection against shorted tube elements, the normal safety and monitoring things (all able to be controlled remotely and monitored remotely)

They put it into a 2-1/2 ton truck and powered it off a self-contained diesel mounted on the truck. They tested it into a dummy load and all worked FB. Diesel was LOUD but not too bad and transmitter hummed right along at 5KWcontinuous for RTTY, 10KW for CW and 10KW PEP for SSB. (I asked 'em "why don't you go for 20KW PEP for SSB" and they said 'Nope, 10KW PEP is fine for what we want to do!"

Needless to say, when test day rolled around they parked the truck WAYYYY Out in a field about 1/2 mile away and ran control cable (shielded) to the test setup. They had a LARGE diameter mobile whip mounted on the back of the truck.

They remotely fired up the diesel and when the gauges said "OK" they dialed up a frequency in the 12 MHz band and let 'er rip. PUt out a solid carrier (NO ID) and watched.

Well, things were fine.. for a few minutes. Then the output VSWR gauge started showing increasing SWR. The autotune monitor showed that the autotune was adjusting and the output was a nice, clean, 5KW.

THEN the VSWR shot off the scale, the autotune couldn't match anymore and the TX shut down. They powered it downand went to see.

Well, they found the antenna GONE! All that was left was a 1 foot stub at the antenna terminal. They founda few blobs of metal on the ground and the end stub of the antenna was blobbed and melted and scorched.

One of the engineers said, "DAMN! What happened? It was SUPPOSED to work!" Another guy said, "What about the corona ball? Didn't you have a coronoa ball?" The first engineer said (with a very pained look on his face), "UMM. NO. Well..(sotto voce to himself.. #@^%#) as he realized he'd screwed up.

Long story short. They rebuilt the antenna, put a VERY large copper corona ball atop it and re ran the test later. IT passedwith flying colors!

THIS transmitter was NOT run near humans cuz ANSI regs said UH UH! NO WAY.

But it was neat...

73
Chuck K3FT

BTW, the power feed to the filaments was SOLID BUS BAR 1" on a side.

The plate voltage wires were 1/2" diameter white specially impregnated HV cable good to 50KV
I would suspect the best those CB"ers were dong was 4-500 AMPS at 12VDC. about 4-6KW available. Figure they were putting out about 3-4KW max on mod peaks and that's generous considering the small diameter feed cables.

W5HTW

03-11-2004, 03:42 AM

Aye, 10-4, there bubba, I'm gonna parallel 70 Sanyo 1KW microwaves, hook 'em to a barbed wire fence, and charbroil steaks on the hoof. For sure, for sure, there buddy, aye, 10-4. In fact, really BIG 10-4. Like 10-4-70?

Whoops. Can't do that on my house wiring. Gonna have to buy a 100 KW generator.

W1RFI

03-11-2004, 11:48 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KC8QMU @ Mar. 09 2004,16:31)</td></tr><tr><td id="QUOTE">By "know-how" I mean ingenuity and maybe the interest in building something. #When I see the number of hams paying big bucks for a simple pre-assembled dipole I can't cut on anyone that turns a vehicle into a generator.[/QUOTE]<span id='postcolor'>
I am curious -- just how many hams have you actually observed buying a pre-made dipole?

In many cases, it is simply a matter of convenience. If a ham already has the wire and the insulators and the center insulator, it is cost effective to build the antenna, and easier than driving to the store. But a ham that doesn't have a spool of #12 hardened copper laying about would probably find it more cost effective to buy the antenna, just to avoid having to buy the wire that is not all that easy to find.

There is also the question of convenience, where it is worth a few dollars to a ham to not have to order all the components separately and spend an hour or so measuring and cutting (and untangling) the wire.

I can think of a couple of occasions where I needed a dipole in a hurry and purchased one at Lentini because we had used up all of our supply of insulators. Your premise that all those that buy dipoles are not as ingenious as those that think they are generating 70,000 watts from 4 alternators wired in series is not nearly as convincing to others as it might be to you. Do you believe my purchasing a dipole antenna is proof positive that I am not "ingenious?"

If you can't cut on people who have no clue that they could not be generating the power levels the think they are generating; have no clue about the RF safety aspects of what they are doing and do not have enough of a clue to figure out that committing a serious federal felony may be about the dumbest thing they could brag about in public, who can you cut on? Hams that buy dipoles?

73,
Ed Hare, W1RFI

k3sam

03-11-2004, 12:58 PM

Another reason 10 meters is out of control...

http://cgi.ebay.com/ws....EBWA:IT (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4674&item=3082236574&ssPageName=STRK:MEBWA:IT)

or Click Here (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4674&item=3082236574&ssPageName=STRK:MEBWA:IT).

ai4ep

03-11-2004, 02:33 PM

http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif ....$275.00 for " that " http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif ( r o f l ) ...guess it IS like the old saying " a fool & his/her money are soon parted " !! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif ( lol )

k3sam

03-11-2004, 02:51 PM

AH YES, but it's the BEST radio he has ever had / sold / heard ... care for a ride in my Pinto ? #The BEST race car I've ever seen ! #My A-13 tires can almost lift the front end ...

I'll meet you on 10 meters tonight, Channel 16. #<span style='font-size:8pt;line-height:100%'>hehe hehe</span>

03-11-2004, 05:22 PM

Another 'fun with RF' story.

The Customer ordered a medium power RADAR. (Medium power to them is about 5 megawatts peak output power, about 3-4KW average power)

Anyway, I got call to witness acceptance test. Go to site, they set up. Make all calls to let folks know 'We're gonna radiate!'. Key transmitter.

After about 20 seconds the power amp kicks off and the 'HI VSWR' lite illuminates.

Tech resets all items, goes outside, checks all connections. All are good. Comes in, fires up transmitter. 2 seconds later same problem. TX drops off line, HI VSWR light illuminates.

Tech scratches head. Says, "I don't understand! worked fine two days ago on the dummy load! Antenna is good becuase we checked it before we hooked it up!"

He tried it one more time, NFG. Then... he and I noted a slight odor in the RADAR shelter. It smelled like chicken that had been put into the oven for too long and was cooked AND a bit burnt!

As we looked at each other the smell got stronger. He went over to the place where the waveguide connected to the TX antenna switchbox and sniffed. He said, "IT's coming from the waveguide!"

I looked at him and he looked at me and he said, "I wonder if something is in the waveguide?" I said, "When you unhooked the dummy load and the hooked up the antenna did anything get inside?" He said he had checked but there had been about 1 hour from the time the waveguide was open to the outside and when he connected the antenna.

He ran out and disconnected the waveguide at the shelter entrance. I went out with him. When he did, he stuck his face near the entrance and then quickly backed off wtih a VERY sick look on his face. He said 'HOLY (**&! That stinks!!'

He went and got a long stick and began to probe the waveguide. Well, what he pulled out was a rather blackened charred remains of two pigeons. Totally cooked. Charcoal broiled, in fact.

HE and I busted out laughing, in spite of the gross sight we were seeing. Couple other techs came over and we showed 'em the birds. Of course.. ALL the comments started up and it continued for some time.

Downside.. it took them 3 hours to clean, scrub, and dry out the waveguide. It took another 3 hours to fully validate that the waveguide had not been affected and it wuold work fine. (IT passed all tests).

They reran tests and RADAR passed.

The engineer who performedthe failure analysis reported the following. (I summarize)

REASON FOR FAILURE.

"When waveguide port was exposed to open environment and left unattended, two pigeons flew into the waveguide and walked to the end nearest the transmitter output port. They then stayed there.

Technican returned and attached antenna waveguide to shelter waveguide port. Due to fact that localized air conditioning units were running, technician did not hear pigeons cooing souinds or movements.

Technician entered shelter and powered up RADAR in preperation for submittal tests. RADAR transmitter was energized by in the "SAFE - NO RADIATE" mode. Government QAR arrived and technician began test.

Technician enabled RADAR by engaging 'RADIATE ENABLE" and proceeding to key the transmitter with normal operational methods. Approximately 20 seconds later system detects HI VSWR condition and saftey interlocks remove transmitter from TRANSMIT and return to SAFE-NO RADIATE mode.

Alarm indicators display 'HI VSWR' condition. Technician retries one more time and same results occur. At that time both technician and Government QAR detect odor of burnt material entering shelter.

After determination of location, technican removes waveguide from shelter port, investigates, and discovers the well charred remains of two pigeons. Visual evidence, based on location of major areas of burns, shows that pigeons must have been within 6 inches of output port of klystron and receiving direct impact of 5MW peak RF power. Estimates of time to cook approximately 30 seconds."

=================
Anyone for broiled squab???

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

Who says we RF guys never have any FUN?

AG3Y

03-11-2004, 05:33 PM

I can't beat that story, and won't even try! But I can tell you that a high powered UHF TV station that I used to work for had a full-blown slot-loaded antenna mounted on the ROOF of the transmitter building! I asked then what the heck THAT was doing there, and they told me that if their tower ever collapsed, they could kick over to the "emergency" antenna and continue broadcasting!

"Now while I'm engineering at this place!" says I !

Can you imagine how strong an RF field that antenna would have put out 5 feet above your head? ? ? It boggles the mind ! Roast Pigeons, indeed !

73 from Jim

03-11-2004, 06:16 PM

AG3Y noted ".....I asked then what the heck THAT was doing there, and they told me that if their tower ever collapsed, they could kick over to the "emergency" antenna and continue broadcasting!

"Now while I'm engineering at this place!" says I !

Can you imagine how strong an RF field that antenna would have put out 5 feet above your head? ? ? It boggles the mind ! Roast Pigeons, indeed !"

Jim, you'd be able to tell when the effects were taking place. They'd all be walking around mumbling things like

"TAIN FOAR!"
"BOY HOWDY, FER SURE!"
"MERCY SAKES!"
"WE BE DONE, DOWN, AND GONE!!"

"CATCHY ONNA FLIP SIDE!"

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

w3bny

03-11-2004, 06:39 PM

And that is why I just looooove Radar!

When something goes wrong...HORRIBLY WRONG.. in the modulator/tubes/waveguide boy will you know it!

Shorted PFN's...Catastrophic TWT arcs....ATR swtich faults....needle guns on the waveguide....carbonized rotary joints....wrenches left inside waveguide...greasy mitt marks on CFA ceramic windows...ozone...ahhh good times...good times... http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

AG3Y

03-11-2004, 06:49 PM

AWWWW, we had a dummy load burn up on us once, and never even knew it until the water started looking a little dis-colored ! ( The water itself absorbed the RF in this particular dummy load ! )

Anyway, there was a 2" diameter hole burned through the center element, all the ceramic insulators were coated with displaced copper, water was leaking all over the place. . . and this was all taking place INSIDE the Coax ! ( the coax being somewhat over 2" diameter solid copper tubing ) Yup, High Power RF at UHF frequencies can be NASTY stuff !

73 from Jim

N5RLR

03-11-2004, 07:12 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (k3sam @ Mar. 11 2004,07:58)</td></tr><tr><td id="QUOTE"><span style='color:orange'>Another reason 10 meters is out of control...

Click Here (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4674&item=3082236574&ssPageName=STRK:MEBWA:IT).</span>[/QUOTE]<span id='postcolor'>
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE"><span style='color:red'>ATTENTION EBAY POLICE: THIS ITEM IS PERFECTLY LEGAL ACCORDING TO FCC GUIDELINES AND IS IN ACCORDANCE WITH EBAY ITEM LISTING STANDARDS! IT IS BEING SOLD AS A 10 METER RADIO AND I CAN NOT BE HELD RESPONSIBLE FOR HOW THE ITEM IS USED ONCE IT IS SOLD,AS WITH ALL ITEMS IN ALL AUCTIONS!</span>[/QUOTE]<span id='postcolor'>
<span style='color:blue'>Err...guilty conscience, here? http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

"240 channels" and the photo shows Channel 19.

Puh-leeze.

Just admit that it's an opened up, third-world sweatshop Cobra clone, and be done with it. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif</span>

KC8QMU

03-12-2004, 01:33 AM

RFI,

All you have to do at a hamfest is be awake to see hams pay big money for simple antennas such as dipoles.

I wish I had enough money to where it would be convenient to pay big bucks for a simple antenna over building it. I built my antenna from scrap wire and wire fence insulators from the local farm store, along with some twin lead. I think I have a total of about 10 bucks in my wire antenna. But if you have an unlimited supply of money I imagine it might be more convinient just to buy one, I guess.

I'd rather see someone that is misguided but actually interested in radio get into the hobby and learn something from it rather than have more hams that get licensed but never get on the air, or have the "shack on a belt" mentality. http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

03-12-2004, 01:38 AM

For EBAY, all you need do is send them a copy (paste) of Riley's recent letters which state that a rig that will operate 10M/11M is neither legal OR permitted for sale in the USA.

it is, what is referred to as, a 'non-certificated' piece of equipment.

So the idiot who is selling that is (of course) talking through his rather filled up with bovine effluvia hat! http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

More RF fun.. AG3Y.. I've heard about that.. but since our RADARs operate 'just a bit ABOVE' the UHF band I never get to see the failures.. but I've HEARD about 'em.

The 'bestest' one (as far as making lotsa smoke. fire,and stink was the one where they had a RADAR transmitter for a BIG aircraft used for command and airspace control. (Big rotating antenna, you get the idea! HI.

Anyway.. it uses a AC to DC converter to generate the HV for the final. Input was 440VAC, 3 phase, 400 Hz. Output was (forget the voltage but it was high enough to need a good dielectric gas to keep things from arcing over! HI) THe current was rated for 400 AMPS continous. A real HONKER of a power supply! Used solid rectangular copper buss bars to transfer the DC voltage to the HV stage.

Anyhow.. they are testing this supply to verify it will handle the load, work under load, and giving it a life test.

As the tech related it to me, the supply had one of the output filter caps (oil filled BIG HONKING VALUE) short internally.

The breakers popped and shut it down but NOT quite fast enough. (These were slow-blow mechanical breakers, not the fast acting magnetic kind!http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

There was a VERY BRIGHT flash of WHITE light. The smoke billows out like a volcano, the sounds of SNAP CRACKLE POP P P P PPPP *BANNNG!!!!* are heard as the cap exploded and THEN the breaker popped with a loud BANG! and the final sound was the sound of high-pitched squeal of the smoke alarms in the test area.

There was oil all over the entire test setup, cap guts embedded in the plastic sides of the test box, smoke marks all over the box and a VERY scared technician lying on the floor rubbing his kneecap where it banged into the cabinet as he reflexively lunged off the stool and tried to make it to the door to escape.

And the stink! They killed the power and opened the box! (MISTAKE!!!http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif I was told it was like a mixture of 1000 burnt resistors smell mixed with OVERHEATED oil.

I'd have liked to have seen that, but missed it. But the tech that witnessed it told me it was something like he'dNEVER seen before!

RF, HV, and 'things that go ZORCH in the night'.. What fun!

73

K3FT

KC8QMU

03-12-2004, 01:57 AM

Those things need smoke to work! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

If you let the smoke out they are worthless!!! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

I've learned a lot about things by letting the smoke out!

Sometimes you need to burn to learn! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

W5HTW

03-12-2004, 02:26 AM

We had a fun one, too. Rather surprising, to be honest. I missed it, unfortunately, but saw the results.

Had a 10KW HF transmitter up, hooked to a garbage-can sized balun (30 gallon can, I would think) Fed with RG217 I believe was the designation - 1-7/8 inch semi-rigid coax. The balun met a pair of wide-spaced feeders which in turn went to a 1600 foot 3-wire rhombic (400 feet per leg)

One day the balun shorted. The man who witnessed it ducked, as he thought he was back in "Nam." (For you young folks, that's short for Vietnam and was the site of a war. Something about Fonda and Kerry?) He explained it to me. "The G--- D--- coax, (running from the transmitter, up 20 feet to a ceiling rack, across 40 feet of ceiling, then down 10 feet to the balun) disappeared. There was a flash of light, a clap of thunder, and suddenly it was raining tiny black particles throughout the transmitter room." He related that his ears were ringing. I later saw the black "soot" covering everything. We had a crew in to clean stuff up. Actually I wish I had seen it! Why did the balun short? We never knew. Just tired, I guess.

But it was a long, long ways from 70KW!!

On the other hand, the same engineer related to me a story about a station he helped build in the Philippines. It was a TMC, 500 KW VLF station. The 'exciter' is itself a 50 KW transmitter, followed by, I believe a 100 KW amplifier. All hooked to a massive vertical, and designed to be used by the US Navy. They were in test phase, and had run the 50 KW exciter directly to the antenna with excellent results. They hooked up the amplifier (which took a couple of days) and tried that out, running it up to the full 100 KW or whatever it was. That, too, worked fine.

Soon afterward (soon, meaning like a couple of weeks) they were ready to test the output stage. They had it all hooked up and they fired up the exciter and amplifier 'straight through.' All was well. They then put the amplifier online, at I think 200 KW. It worked beautifully. Acceptance testing was going well.

They cranked it up to 250 KW and suddenly it shut down. Hmmm. They went through it again. 200 KW and all was well. At 250 KW, or maybe it was 300 KW, it shut down. And with a bang of relays. But everything checked fine in the transmitters.

Then they brought it up the third time. As they gently boosted it to 250 or 300 KW, now late at night, as they were working lots of overtime, another tech came in the door and told them "You should see this!" They went outside. The corona from the vertical was lighting up the parking lot. And as the TX went higher, the corona stopped and there was a massive arc to the guy wires.

As I recall now (been a lot of years) they had to redesign the tower and ran months behind schedule. I would have liked to have seen that, too. In fact, I would have just liked to have seen the TMC transmitter!

But back to the CBer! As station engineer of a Class B 50KW (ERP) FM station, our 17KW transmitter was bigger than the CBers truck. And I recall as a teen visiting the old KOA AM 50 KW transmitter east of Denver. Bigger than an office building!

Enjoy
ed

K4KWH

03-12-2004, 03:43 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (K3FT @ Mar. 10 2004,20:30)</td></tr><tr><td id="QUOTE">I saw that site and marveled at the never-ending 'ego boost' that these types of folks like to get when they use those claims like '70KW' output from their 'mohhh-byles'! #http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

They don't know any better and those that do keep their yaps shut, most of the time. #

To give you an idea of what's required to generate 10KW of RF on HF (from a mobile environment) without cooking the gear....

The 'bestest' demonstration of a high power mobile was a #piece of HF military gear that I had the pleasure of observing in a test situation many years ago.

Seems the Customer wanted a MOBILE HF transmitter with REMOTE operation. (Note.. remote operation! VERY important to the story)... so they could have solid comms almost anywhere they wanted. #They wanted 10KW PEP, 5KW DC output power. Modes desired were SSB and CW/RTTY. They spec'd output at being able to be produced into max 6:1 mismatch, without time limitations, minimum 5KW output for RTTY and 10KW PEP for SSB, 10KW for CW.

Requirements were 12VDC feed with appropriate voltage/current inverters to generate necessary DC voltages for fils, grid, plate, screen, etc.

<I won't mention WHICH Customer, but suffice it to say they had a lot of #bux floating around in cubbyholes that weren't labeled with the accurate names of what they were REALLY for! HI! >

Anyway.. the contractor built a 4 tube xmtr using 4CX10000 tubes. #Class C for CW/RTTY, Class AB1 for SSB. #Autotune antenna matching, input voltage foldback for protection against shorted tube elements, the normal safety and monitoring things (all able to be controlled remotely and monitored remotely)

They put it into a 2-1/2 ton truck and powered it off a self-contained diesel mounted on the truck. #They tested it into a dummy load and all worked FB. Diesel was LOUD but not too bad and transmitter hummed right along at 5KWcontinuous for RTTY, 10KW for CW and 10KW PEP for SSB. (I asked 'em "why don't you go for 20KW PEP for SSB" and they said 'Nope, 10KW PEP is fine for what we want to do!"

Needless to say, when test day rolled around they parked the truck WAYYYY Out in a field about 1/2 mile away and ran control cable (shielded) to the test setup. #They had a LARGE diameter mobile whip mounted on the back of the truck.

They remotely fired up the diesel and when the gauges said "OK" they dialed up a frequency in the 12 MHz band and let 'er rip. PUt out a solid carrier (NO ID) and watched.

Well, things were fine.. for a few minutes. Then the output VSWR gauge started showing increasing SWR. The autotune monitor showed that the autotune was adjusting and the output was a nice, clean, 5KW.

THEN the VSWR shot off the scale, the autotune couldn't match anymore and the TX shut down. #They powered it downand went to see.

Well, they found the antenna GONE! All that was left was a 1 foot stub at the antenna terminal. They founda few blobs of metal on the ground and the end stub of the antenna was blobbed and melted and scorched.

One of the engineers said, "DAMN! What happened? It was SUPPOSED to work!" #Another guy said, "What about the corona ball? Didn't you have a coronoa ball?" #The first engineer said (with a very pained look on his face), "UMM. NO. Well..(sotto voce to himself.. #@^%#) as he realized he'd screwed up.

Long story short. They rebuilt the antenna, put a VERY large copper corona ball atop it and re ran the test later. IT passedwith flying colors! #

THIS transmitter was NOT run near humans cuz ANSI regs said UH UH! NO WAY.

But it was neat...

73
Chuck K3FT

BTW, the power feed to the filaments was SOLID BUS BAR 1" on a side.

The plate voltage wires were 1/2" diameter white specially impregnated HV cable good to 50KV
I would suspect the best those CB"ers were dong was 4-500 AMPS at 12VDC. about 4-6KW available. Figure they were putting out about 3-4KW max on mod peaks and that's generous considering the small diameter feed cables.[/QUOTE]<span id='postcolor'>
HeeHee!

Would a copper toilet tank float make a big enough corona ball? That was a funny story! Thanks!

73

ai4ep

03-12-2004, 04:53 AM

http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif (lol) glad I dont have to worry about hearing such stuff...back when I was into CB radio, I only had 3 of my CITIZENS BAND rigs swiped from my vehicles...but after 14 years of being affiliated with AMATEUR radio, not a single AMATEUR rig has been swiped from any of my vehicles... geez...wonder why ? http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

KC0W

03-12-2004, 06:01 AM

Thanks much for all the replies to my original post about the 70KW mobile CB'ers. Looks like the header to this topic should be changed to 3KW (if their lucky) Mobile CB.

If your bored, check out the 4th video down from the top of the page link. The guy who has the white Surburban. This NUT has a 4-square antenna array on his truck for 27 MHz. It's hard to tell, but it looks like there might be a 5th antenna in the center of the 4-square. A 5-square?

Takes all kinds,

Tom kcØw

w5klb

03-13-2004, 08:33 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (kc0w @ Mar. 09 2004,22:11)</td></tr><tr><td id="QUOTE">Ya, I know some of you have seen this site before, for those who have not, check out what our CB "friends" are running mobile. #

70KW radio (http://www.bigradios.com/avis/)

# # # # # # # # # # # # #Tom kcØw[/QUOTE]<span id='postcolor'>
Good Grief!!!

What are they trying to do-radiate lightning of the top of the antenna or are they trying to communicate with Elvis?

With that much power I would think that they would be using a V12 Detroit Diesel as a prime mover. One thing is for certain-you can bet they would be able to splatter just about all of the 11 meter band and maybe a few others too.

"Hey Cleatus, let me put down this here bear and let me put some far to the wire-tain fer?" Beeeeep!

ai4ep

03-14-2004, 02:50 AM

http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif What ? ! Another CB topic in an AMATEUR radio website !! http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

03-14-2004, 04:28 AM

Well there was a !kw mobile running in the back of a herse.It was called the "Herse mobile" and was written up in QST so I could find it.Water-cooled tubes because there was'nt any air cooled tubes then.

Then there was KGEI operating out of #Treasure Island in S.F Bay with a power of 25kw pretty good when most
B.C statons were a max of 500w.It ended up broadcasting on short wave for Voice of America.

#Absolute power corrupts absolutly

70kw cb rig must be an urban legend

# # # #WA6FFV spookey0071@hotmail.com

w9ray

03-28-2004, 07:06 PM

I wonder what they use for a power meter..probbly just hook a few rat shack meters together...Hi Hi

I think it's funny how they say a Toshiba 2sc2290 transistor puts out 120 watts out at 15 volts and #200 watts at 20 volts.. When the Toshiba data sheet rates them at 60 watts pep... at 12.8 volts.. wil they even survive at 20 volts long...?

http://www.davemade.com/mobile.htm

Why dosnt the fcc shut down this sob..?

mobile 3cx15000 ...84kw. # whatever..... where do the get the 10kv at 5 amps from for the plate.. not to mention #the heater... its only 160 amps... then they are only rated to 25KW.. not 84kw

and several RR train alternators....i didnt know trains have alternators that are smaller than a Suburban???
This is stuipd...... why did i even look at this post.... Hi Hi

03-29-2004, 04:14 AM

As i dont condone this act, the generators there using look to be Gentecs 6.5kw units these opperate at 120/240 at 60hz. We use these in a air compressor unit as a gen option, hp needed to operate these at .8 pf would be 8.775 hp. Now they could be using gentecs 3ph 208 13kw rigs and they would need 17.55 hp per unit giving them 208 3 ph at 108 amps per rig using 4 (like it looks in the pictures) would be a usable total of amps of 432 at 208 thus creating 89,856 watts of AC power. The HP needed at 1800 rpm (these are two pole alts) would be 120.15 hp We manufacture a 3ph 208 NG unit what produces 100 kw using a 454 chevy eng at 1800 rpm. All this shows the KW can be made to power a good size amp system, i have installed many Gen sets at TV and radio staions pushing more that 100,000 rf watts and only used 125 kw back up gensets to power them.

I only remote care about this as were working on board power systems up to 75 kw for PTO truck drives....

ai4ep

03-31-2004, 02:21 PM

http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif case to note: I have had no less then 3 ( three ) citizens band rigs swiped from various vehicles through the years...however, not ONE amateur rig has been stolen in over 13 years.

KG4RYT

04-02-2004, 07:21 PM

Think about this, as this guy is traveling down the road all the birds sitting on the power lines fall over from to much rf. http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

When this idiot is driving through town all the old men with pace makers either pass out, or grab their chest and fall over dead http://www.qrz.com/iB_html/non-cgi/emoticons/confused.gif #

The whole time he is shooting skip over in dx land he wonders why he feels so woozy http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

He wonders how much fire is needed in the wire http://www.qrz.com/iB_html/non-cgi/emoticons/sad.gif

What few brain cells are left after the radiation exposure are thinking of how can i get just a few more watts out of my big time moble, smoke blowing radio, or how do i get back home.

K9STH

04-02-2004, 11:33 PM

Collins used to make all sorts of 20 KW output mobile linear amplifiers and even made a few 50 KW. These covered 2 to 30 MHz and had autotune circuits for antenna loading. One day someone got the idea as to see if one of the 20 KW linears could load a long wire laying on the ground. Somewhere between 150 and 200 feet of wire was hooked to the antenna connector and the linear was "locked down". Oh, by the way, did I mention that these linears were continuous power rated!

The wire started buring at the far end and over a period of time the wire burned away until only about 3, or so, feet was left. At that time the amplifier's protective circuit shut it down since the auto tuner could no longer match the "antenna".

These were definitely "mobile", but they were normally installed in the complete shelter units that were mounted on the back of large trucks.

Glen, K9STH