My opinion on: HF amps and hf beams

[VE7NOT]

Been on hf just over a year and have noted many times the stations running amps and beams.

I favour thae later from 30m up. Many times statiosn have turns beams towards my dipole and have improved greatly.

But does the beam need to be 100' up? Probably not. I read one a ham on Mona Loa 14000' up heard no differance between there and sea level.

So a beam could be say 20' up above metel building. (unless your in NYC) http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif

Now amps. 80m Excellent. 160m Okay. 40-10m. USELESS. 1-2 units on a signal meter is often quickly taken away by qsb.

No locally is different. 1kw on 10m is quite good on a damp night. Better then 100wts.

Great.

My observation. I think 1w is enough for 20 and 17 http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

[KI4NGN]

Hmmm.... 1 watt is enough. OK. Let's see, if you go from 1 watt to 512 watts, that's a 27 db increase in signal. I agree, hardly worth it. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

[AA0CX]

What do damp nights have to do with it? http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

[W4HAY]

Once had a 3-el. tri-bander. When I moved 20 years ago I never put it back up. Strictly wire antennas now. I don't contest, but do chase DX.

I only use the Amp for 80 & 20 M SSB emergency nets, and occasionally to talk to a friend on Sao Tome. The QRN he experiences is murder! Otherwise it's 50 Watts & a dipole -- or whatever wire conglomeration happens to be hanging between the trees at the time.

Cutting through pile-ups requires a bit of sneakiness, but ya get a nice feeling of accomplishment when it happens!

[N2RJ]

Quote[/b] (VE7NOT @ Sep. 30 2006,23:24)]But does the beam need to be 100' up? Probably not. I read one a ham on Mona Loa 14000' up heard no differance between there and sea level.
But I always hear HK3OZ (formerly HK3AK) and he's high up in Bogota, Colombia around 6900 feet and he's always a S9+ from the mobile.

[n0iu]

Only YOU can determine if something is worth it to you.

I also think you need to do more studying about antennas and propagation in general. With VHF and above, elevation is the crucial factor since it is line of sight. With HF, the crucial factor is height above the ground (NOT height above sea level) and takeoff angle. The objective with HF is to bounce your signal off of one of the layers of the ionosphere. This is why the op at 14,000 ft in Hawaii has no particular advantage on HF other than being able to operate from Hawaii!

Scott NØIU

[n2nh]

There are people who work the world QRP and a few QRPp. Power is only part of the equation. Then again, I've heard more than a few CB'ers that are running with both a HF Amp and HF Beam.

[ka5s]

Quote[/b] (AB2MH @ Oct. 01 2006,08:51)]But I always hear HK3OZ (formerly HK3AK) and he's high up in Bogota, Colombia around 6900 feet and he's always a S9+ from the mobile.
I've worked EI, UI, JA and 3D2 with 2 watts, walking around with an FT817 on a neck strap and an antenna on the rig. This does not mean 2 watts and a portable is all I need! There are many other factors that determine whether you will be heard (or that someone else can be heard) on a particular frequency, over a particular path, at a particular time.

BTW, South America to the US is a special case; trans-equatorial proapgation is often better than propagaion East-West.

Added: When D-layer absorption is high, HF, and even more, NVIS HF, needs high power to be reliable.


Cortland
KA5S

[VE7NOT]

Quote[/b] (AA0CX @ Oct. 01 2006,04:35)]What do damp nights have to do with it? http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
On damp or rainy nights I note a good increase in 10 and 11m signals. The 10m net on sundays often shows stations that are normally below the noise level jump to a good s2 or 3 on a damp day/night.

[KB3LIX]

"Cutting through pile-ups requires a bit of sneakiness, but ya get a nice feeling of accomplishment when it happens!"

I'll second that !
http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

[w8cbc]

160-metre operation has been phenomenal for me this weekend. I was outdoing stations with amplifiers and "proper" dipoles. I suspect that it is mainly due to wet weather making my counterpoise into a solid RF ground. Perhaps I don't need an amplifier. A sprinkler system may do just as well. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

I would venture a guess that this sort of thing is going on with 10 metres out there.

[W5IEI]

I always run legal limit,unless I need more http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

[N7RJD]

Quote[/b] (VE7NOT @ Sep. 30 2006,15:24)]My observation. I think 1w is enough for 20 and 17 http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
Did you actually mean 1w or did your finger fall asleep and miss the "k" for 1kw?

[nz3m]

I think it all depends what you are into.

On 40m to 10m HF, power and big antennas let you bust through pile ups. #They can also give you a big signal to brag about. You don't "need" it though. #A 55 sig is as readable as 59+. #On the low bands, an amp is good to get your signal above the QRN. #

Now, on VHF/UHF it's a different story. #The more the better.
#RN6BN 64x 15 on 2m (http://www.73.ru/equipment/144_64/144_64_1.jpg) #http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

Dave

[KB3LIX]

"A 55 sig is as readable as 59+."

I had a station give me a 5-1 one time. I didn't care, the 5 is what was important, readability. The one just indicates that propagation conditions were weak.
Due to the fact that he was on Diego Garcia island in the middle of the Indian Ocean, #
he could have given me a 5-0 for all I cared.

Approx 9600 miles from 100 watts into a homemade center fed Zepp at 6.5 meters above ground level, and he heard me......
What do I care about signal strength,

HE HEARD ME !!!!!!!!!!!!!!!!!!
And that's all that matters !!!!!!!!!!

I still get the "willies" thinking about that contact.

[WA2ZDY]

32 years of hamming. Never had an HF amp, tower or beam. Never will either. No need.

[WB2WIK]

For me, it's a matter of making the most of the limited operating time I have. I often can't be on when bands are wide open, which is the time when low power and a wet noodle seem to work. I operate when I have spare time to do so, and sometimes the propagation is quite poor. Sometimes I hear "there isn't any" propagation at all...and most people just switch to OFF and do something else.

Then, I get on the air and make contacts. I can't make them with low power and small antennas, so I use high power and as much antenna as I can muster, which is usually a beam on a tower. Hardly a day goes by that I don't get a report of, "You're the only station I hear. The band's dead. But I copy you fine..." and then we get on with a contact.

During such a contact, if I switch from the beam to a dipole, and then reduce power to 100W, that's the end of the contact. I've done that, many times...and yep, that's what happens.

WB2WIK/6

[K5FH]

It's really a matter of dollars per dB or, more precisely, diminishing returns.

Here's my (admittedly SWAG) analysis of a simple HF system:

On a $/dB basis the amp is the cheap and quick way to go. #Going from 100 watts to 800 watts is a 9 dB increase (1-1/2 S-units, assuming 6 dB/S-unit). #An Ameritron AL-811H costs about $750 new. #That's around $84/dB. #Going to 1500 watts is approximately a 12 dB increase; ann Ameritron AL-800H is $2700 which would be $225/dB.

A 40 ft Rohn 25G tower would run about $800 (including freight) or so. #The base (digging the hole and pouring the concrete) would be probably $1000 including labor (I'm assuming you don't dig the hole yourself). #A decent rotor (Yaesu G-800SA) is around $325. #A small, minimum tribander (Hy-Gain TH2MK3) can be had for around $350. #Including the cost of the rotor cable, coax cable and the case of beer for your friends who help you put up the tower and antennas, you have now spent around $2500. #The forward gain of your new antenna is about 3 dB on average. #Figure another 3 dB for height gain and your dollars per dB figure is about $415.

Note that the above example is what most of us would consider a bare minimum tower/beam installation. #Go to a 50-ft. crank-up tower, a heftier rotor and larger beams and we're in the $5000 to $8000 range for the antenna system. #Assuming the larger system would give you around 8 dB forward gain and 3 dB for height gain, the dollars/dB figures are $450/dB to $750/dB.

So, adding the cost of the amp ($2700) and the tower/rotor/antennas ($5000), and assuming gain is additive (12 dB for the amp and 11 dB for the antenna), your final cost per dB is $7700/23 dB = $334/dB.

Notice that you reach diminishing returns quickly in large HF antenna systems. #But you are now about 4 S-units louder on average. #On a dollars per S-unit basis it cost you about $2000 per S-unit.

Is it worth it? #Only you (and your XYL, if applicable) can decide that.

Me, I'll stick with wire and verticals and put the difference in my 401K.

[K3STX]

I have run 100 watts since 1978, and about a month ago got a 400 watt amp ($600, not $2700). I did fine barefoot, DXCC on 4 bands (missing 10 meters), 250 countries worked, all wire antennas, and I agree it took more efffort to be a little pistol to work Peter One or Juan Fernandez or ...

But the other night, on 80, I was trying to work CX4SS for about 20 min barefoot (still need it on 80). I asked myself "what if I use my amp?". Using 400 watts got him on my first call.

THAT is why you use an amp. And yes, I did sleep soundly after that.

paul

[N2RJ]

The advantage of having a better antenna system vs having just an amp is that you can hear more instead of just having a big mouth.

Of course if your objective is to just be heard over the others, brute force will work.

[NN3W]

I bought my SB-200 for $250. $27.77 per db. Thats a cheap price to pay for not having to wait a long time in pileups (or not to work them at all)...

[n0nwo]

I have never owned an amp, but I bought a small triband beam a couple of years ago. Sometimes it is fantastic, sometimes the bands are so hot, it don't matter much where you point it.

Minton

[K1OU]

If you hang out much on 75 meters, you would know that an amp helps to swat the flies that try to hijack a frequency, as well as cut through the static when the band is rough. Then again, an amp means about squat if you don't have a decent antenna.

[w8cbc]

An amplifier could have been useful last night in the local 80 metre SSB thing.

The band was "long". Guys running 500 watts were filling the skip zone. Guys like me running 100 watts weren't. A /VE3 was relaying for us.

[K1OU]

Quote[/b] (w8cbc @ Oct. 02 2006,14:59)]An amplifier could have been useful last night in the local 80 metre SSB thing.

The band was "long". #Guys running 500 watts were filling the skip zone. #Guys like me running 100 watts weren't. #A /VE3 was relaying for us.
I have a feeling that with your loop and about 600 watts, you would have no problem doing good business on 75.

One of the best antennas I ever used was a 270 foot delta loop with the apex at about 50 feet, and it was fed in the middle of the baseline with 450. #I used that with an AL811 for a couple of years and had no problem holding my own.

[w8cbc]

No loop here, that's someone else. I end-feed a 360-ft. wire. It does better in 160 and 40 metres than it does in 80. I haven't tried it in the 60-metre channels as I haven't a clue what sort of gain it might have there and want to stay within the proper 50-watt ERP limit.

I wanted to suggest to the rest last night that we move down to 160 metres (those present were capable of it) but the other guys gave up before I could have my say.

[ve2nsm]

Quote[/b] (VE7NOT @ Oct. 01 2006,00:24)]But does the beam need to be 100' up? Probably not. I read one a ham on Mona Loa 14000' up heard no differance between there and sea level. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
True.
The only important height is the HAAT, or height above average terrain. The type of ground, and height above it will affect your take off angle, THAT's the important thing you have to work on.
If you have a 20m meter beam 25' off the ground, you have nothing, or almost nothing, in some cases you won't even see a difference by rotating it, why? because your TOA is so high that it's not a beam anymore, just a piece of aluminium with a motor under it http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

If you look around you should find a chart with a rule of thumb *emphasis on rule of thumb* ot the best TOA for a given band for a given distance to cover with F layer propagation.

If you shoot too low you overshoot your target, if you shoot too high, you risk going right through the layer and never come down again http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif
Many times a 20m beam at 60' will get stronger reports 2000Km away than the same beam at 120'. Everytime the beam at 120' wins if you go very long distances or under low propagation indexes... TOA http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

In my experience, a 60' high threebander is the best do-it-all station, not too high, but high enough to get that low TOA. I rather have my little mosley TA33 at 60' than the big KLM and other monsters at 30' anytime, anytime.

[w8cbc]

I want to set up a five-element 160-metre beam some day.

One of those self-supporting 800-ft. broadcast towers might do for a support.

I suppose I'll have to construct a big scarecrow to keep the helicopters away.
Darn flapping contraptions, perching all over my aerial...

[ve2nsm]

Quote[/b] (w8cbc @ Oct. 02 2006,19:31)]I want to set up a five-element 160-metre beam some day.

One of those self-supporting 800-ft. broadcast towers might do for a support.

I suppose I'll have to construct a big scarecrow to keep the helicopters away.
Darn flapping contraptions, perching all over my aerial...
I new a guy who built a three element for 80m on a 60' boom, the elements were linear loaded and the longest one measured 90' I think. I saw it, and I walked under it's shade, it was mounted on a 130' foot tower around 300' from his house, when at the operating position you could see that baby turn (yes, it had a rotor).

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

[ve2nsm]

Found pictures!
linkefaction (http://tgc.jp-au.net/ve2hq.htm)

I can add that the three towers in line are 120' high and have a 40m 3 element for the first, a 20m 6 element for the second and two 6 element for 15 and 10 on the last one.

Between the three towers were suspended two full size delta loops for 80m in a broadside co-linear configuration (for local 80m work) http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

The tower that is apart from the others is 130' high and has the shortened 80 yagi... with two guys working atop http://www.qrz.com/iB_html/non-cgi/emoticons/cool.gif

[w8cbc]

Right now (leaving out the when-I-win-the-lottery dreams), I'd settle for a 50-ft. tower and enough materials to make a decent 6-metre yagi.

I've been looking at the adverts. Some of those multi-section collapsibles look very interesting.

[MM3XXW]

Quote[/b] (KB3LIX @ Oct. 02 2006,00:29)]"A 55 sig is as readable as 59+."

I had a station give me a 5-1 one time. I didn't care, the 5 is what was important, readability. The one just indicates that propagation conditions were weak.
I absolutely couldn't agree more.

I, personally, have very little interest in what my actual signal is as long as my audio has made it through clearly enough to be read without too much problem to the recipient.

[NN3W]

Quote[/b] (K1OU @ Oct. 02 2006,15:04)]One of the best antennas I ever used was a 270 foot delta loop with the apex at about 50 feet, and it was fed in the middle of the baseline with 450. #I used that with an AL811 for a couple of years and had no problem holding my own.
Yeppers. thats basically what I have now. 270 foot quad with the top at about 50 feet - center bottom feed with a 4:1 balun and coax. Run with a SB-200 - with 800 watts. Can't tell you how much groovy DX I've worked this past week - but YI on 40, 3X on 75, VQ9 on 40, E51 on 40 are but a few examples.

[WA9SVD]

Quote[/b] (K5FH @ Oct. 02 2006,09:35)]It's really a matter of dollars per dB or, more precisely, diminishing returns.

Here's my (admittedly SWAG) analysis of a simple HF system:

On a $/dB basis the amp is the cheap and quick way to go. Going from 100 watts to 800 watts is a 9 dB increase (1-1/2 S-units, assuming 6 dB/S-unit). An Ameritron AL-811H costs about $750 new. That's around $84/dB. Going to 1500 watts is approximately a 12 dB increase; ann Ameritron AL-800H is $2700 which would be $225/dB.

A 40 ft Rohn 25G tower would run about $800 (including freight) or so. The base (digging the hole and pouring the concrete) would be probably $1000 including labor (I'm assuming you don't dig the hole yourself). A decent rotor (Yaesu G-800SA) is around $325. A small, minimum tribander (Hy-Gain TH2MK3) can be had for around $350. Including the cost of the rotor cable, coax cable and the case of beer for your friends who help you put up the tower and antennas, you have now spent around $2500. The forward gain of your new antenna is about 3 dB on average. Figure another 3 dB for height gain and your dollars per dB figure is about $415.

Note that the above example is what most of us would consider a bare minimum tower/beam installation. Go to a 50-ft. crank-up tower, a heftier rotor and larger beams and we're in the $5000 to $8000 range for the antenna system. Assuming the larger system would give you around 8 dB forward gain and 3 dB for height gain, the dollars/dB figures are $450/dB to $750/dB.

So, adding the cost of the amp ($2700) and the tower/rotor/antennas ($5000), and assuming gain is additive (12 dB for the amp and 11 dB for the antenna), your final cost per dB is $7700/23 dB = $334/dB.

Notice that you reach diminishing returns quickly in large HF antenna systems. But you are now about 4 S-units louder on average. On a dollars per S-unit basis it cost you about $2000 per S-unit.

Is it worth it? Only you (and your XYL, if applicable) can decide that.

Me, I'll stick with wire and verticals and put the difference in my 401K.
The only "fly in the ointment" of your theory is that while improving the antenna/tower system buys you both transmit AND receive benefits. Adding an amp only makes YOUR signal louder, NOT the other station's signal. "You can't work them if you can't hear them, even if they can hear YOU you S9++ there. You are probably just cerating QRM."

[NN3W]

Yes, but the converse is also true.

If they can't hear you, but you can hear them, a linear could help.

Local atmospherics are a real issue with so many hams living in suburbs. You often need that extra "kick" to rise above the noise floor which on bands like 75 and 160 can be S5, S7 or S9+

[WB2WIK]

Quote[/b] (ve2nsm @ Oct. 02 2006,16:12)]Quote[/b] (VE7NOT @ Oct. 01 2006,00:24)]But does the beam need to be 100' up? Probably not. I read one a ham on Mona Loa 14000' up heard no differance between there and sea level. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
True.
The only important height is the HAAT, or height above average terrain. The type of ground, and height above it will affect your take off angle, THAT's the important thing you have to work on.
It's really not HAAT on the HF bands. That's important for VHF-UHF, because the propagation is tropospheric. With ionospheric propagation, if you can see the sky you have a shot at working DX.

The variable is how much of the sky you can see, down to what horizon; the other variable is the height of your horizontally polarized antenna above earth ground, not above sea level or above average terrain -- those really don't matter.

It's 100% true that operating from a "mountaintop" on HF is no better than operating from sea level; in fact, stations in Hawaii who often try both (like my QSO with AH6OR in Maui last night) verify that sea level is better almost all the time. My friend Dave WA6DKN operated /KH6 for a week in May and did drive to the summit of Mauna Kea at 14,000 feet using the same mobile setup he used at his beachfront condo and found absolutely no improvement in anything when operating from the mountaintop.

The TOA of your antenna is related to antenna design and height above earth ground, and nothing else. Height above sea level or above average terrain doesn't influence this.

I'd much rather have my 20m 100' above ground in a valley than 20' above ground on a mountaintop, as long as the valley wasn't so deep that I had a substantially positive horizon.

WB2WIK/6

[NN3W]

Well, from a HF DX perspective, low angle signals are arriving at angles of less than 20 degrees. So, if your sightpath is blocked up to 20 degrees above the horizon, you're going to be missing a fair amount of long-range DX.

[WB2WIK]

Quote[/b] (NN3W @ Oct. 03 2006,08:29)]Well, from a HF DX perspective, low angle signals are arriving at angles of less than 20 degrees. So, if your sightpath is blocked up to 20 degrees above the horizon, you're going to be missing a fair amount of long-range DX.
That's a very positive horizon. Most people don't have a +20 degree horizon in any direction, and those who do might have this in one direction but not all. You'd have to be in a pretty deep valley for this to occur.

I live at 900' a.s.l. and have a 3500' hill to the north, 5000' hills to the northeast, 2800' hill to the west, and 2600' hill to the south, and only in one very small direction do I have a +20 degree horizon (measured with sextant); that's directly towards the summit of the 3500' hill north of me, which is only six miles away. In all other directions, my horizon is less than +15 degrees, and in some directions it's less than +5 degrees.

Better still is 0 degrees in all directions, which is what I had when I lived at the NJ seashore in 1985-1987. That was about 10' a.s.l. and a better "radio" location than most.

WB2WIK/6

[K5FH]

Quote[/b] ]The only "fly in the ointment" of your theory is that while improving the antenna/tower system buys you both transmit AND receive benefits. #Adding an amp only makes YOUR signal louder, NOT the other station's signal. #"You can't work them if you can't hear them, even if they can hear YOU you S9++ there. #You are probably just cerating QRM."

Don't assume that transmit and receive will always benefit to the same extent. #We've all seen instances where somebody is received S8 on your 1/4-wave vertical but can't hear you hardly at all.

I didn't say a tower and beam wouldn't appreciably improve your capability; they will in just about all cases. #What I was attempting to illustrate was return on investment and how adding signal gain reaches diminishing returns when calculated on a cost per dB basis.

It's worth it to some people to spend the equivalent of the national debt of some small countries on their stations (i.e., the big-gun contesters) and if they can afford it and it works for them, all well and good. #Some of us have no choice but to make difficult situations work (condo dwellers, small city lots, zoning and CC&R restrictions) if we want to pursue our hobby. #It all comes down to doing the most with whatever resources you have available.

[w8znx]

Quote[/b] (K5FH @ Oct. 02 2006,09:35)]It's really a matter of dollars per dB or, more precisely, diminishing returns.

Here's my (admittedly SWAG) analysis of a simple HF system:

On a $/dB basis the amp is the cheap and quick way to go. #Going from 100 watts to 800 watts is a 9 dB increase (1-1/2 S-units, assuming 6 dB/S-unit). #An Ameritron AL-811H costs about $750 new. #That's around $84/dB. #Going to 1500 watts is approximately a 12 dB increase; ann Ameritron AL-800H is $2700 which would be $225/dB.

A 40 ft Rohn 25G tower would run about $800 (including freight) or so. #The base (digging the hole and pouring the concrete) would be probably $1000 including labor (I'm assuming you don't dig the hole yourself). #A decent rotor (Yaesu G-800SA) is around $325. #A small, minimum tribander (Hy-Gain TH2MK3) can be had for around $350. #Including the cost of the rotor cable, coax cable and the case of beer for your friends who help you put up the tower and antennas, you have now spent around $2500. #The forward gain of your new antenna is about 3 dB on average. #Figure another 3 dB for height gain and your dollars per dB figure is about $415.

consider a bare minimum tower/beam installation. #Go to a 50-ft. crank-up tower, a heftier rotor and larger beams and we're in the $5000 to $8000 range for the antenna system. #Assuming the larger system would give you around 8 dB forward gain and 3 dB for height gain, the dollars/dB figures are $450/dB to $750/dB.

So, adding the cost of the amp ($2700) and the tower/rotor/antennas ($5000), and assuming gain is additive (12 dB for the amp and 11 dB for the antenna), your final cost per dB is $7700/23 dB = $334/dB.

Notice that you reach diminishing returns quickly in large HF antenna systems. #But you are now about 4 S-units louder on average. #On a dollars per S-unit basis it cost you about $2000 per S-unit.

Is it worth it? #Only you (and your XYL, if applicable) can decide that.

Me, I'll stick with wire and verticals and put the difference in my 401K.
prices only true

if an appliance op

have bought Rohn 25 tower sections for
as little as 25 bucks each
( some day might use them )

friend has a barn full
of tower sections, aluminum tubing,
antennas, rotors
all picked up at scrap prices

this did not just fall in his lap
he had to scout around keep his ears open
often had to take down the tower/antenna systems
drive few hours there and back

now has up two towers
150 ft of Rohn 45, 75 ft of Rohn 25
all for scrap price
does all his own tower work

farmer friend with a back hoe
dug the holes for free

he has not cut in to his 401K
to have the antenna system
he dreamed of owning for over 40 years

took few years work, but it is wonderfull

only things he bought new
feed line and some hardware
and the ready mix truck load for the base

lots of scrap yagis, towers and busted rotors
wating to be hauled away

some towers offered
you just walk away and
say thanks but no thanks

but there are good sturdy
well cared for towers
that people no longer want
there for the taking down and hauling away
some times they have been already taken down

its not hard to make yagi antennas
from scrap busted yagis
many rotors can be fixed
there is a place in Ohio that rebuilds
rotors also sells parts and rebuilt rotors

amp
build one
they are dirt simple
think of it as a antenna tuner with
a tube and power supply


harder to find
parts to build amps at the swaps
but mid power 600/800 watt amp
parts are still kicking around

see Richard Measures ugly amp designs
you don't need expensive parts

or buy a non running amp
last amp bought
( Hallicrafters Loudenboomer single 3-400Z )
cost $300 not running
new swinging choke $ 150

could have done it cheaper
but wanted to get it on the air
called Peter D
payed big bucks for the choke

too much
how about four 811A Hammond HL-500
not running $75 one weekend work
and $50 in parts
solid 600 watts out for $125

nothing like power
was ham for almost 20 years before
i got my first amp a busted up SB-200

was hard core qrp op
over 25 years member of ARCI

for years only gear was Ten Tec 509 Argonaut
a converted Johnson cb transceiver,
Johnson Match Box,
R-390A receiver and a 2 meter fm rig

spent all my time on 15 and 10 meters
worked tons of dx

but having a nice long rag chew on 75,40,20
forget it

last few years have become
a late night 80/75 and 40 meter op

still love to run qrp
late winter nights have run as little as 100 mw
on 80 meters
but most often run 2 to 14 watts

summer nights 75 meter fone
want to rag chew
you need at least 300 / 400 watts
600 / 700 even beter

re yagi antennas

would always rather have
home brew 3 el yagi or 2 el quad
only 20 ft above ground
than
store bought ground mounted 1/4 wave trap vertical

good yagi or quad even if low
help you hear better
if for no other reason than
helps knock down received qrm

line noise from down the block
thats when a beam is always
better than a vertical
even if its only 20 ft above the ground

where was i
dam wasted 2 1/2 hours
trying to compose this
so it can be read

man need to get back to work
before the boss finds out

oh wait
am the boss

still in the stacks

READ OR DIE !

mac

[NN3W]

my god, was that a haiku or did someone go ape with the carriage return button?http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif

[K5FH]

znx,

Your post proved my point.

I said, "it all comes down to doing the most with whatever resources you have available." #Most of us aren't lucky enough to have resources such as friends with barns full of ham-related materials and backhoes to dig foundations for recycled junk towers. #Unlike some of the big guns we don't have megabucks and forty acres to put up humongous arrays. #

I have rebuilt my share of junk radios and antennas over the years. #Some of it worked well and some didn't. #That's part of the game. #In most circumstances it's easier and cheaper to buy new than rebuild junk. #Yes, sometimes you have no choice but to rebuild a wreck but in making the decision to build or buy I consider the value of my time. #

If I had a source of cheap or free aluminum tubing and scrap tower sections I would probably have built a tower and beam system by now. #But I don't, so I haven't.

But I still get a lot of fun out of the hobby. #Which, last time I looked, was supposed to be the point of the whole exercise.

[G3OZN]

"If I was a rich man" diddle diddle didle didle dum

Well I'm not, and until my xyl wins the UK lottery ( I don't do it !) I'll stick with my 60ft wind up (and down!) "Versatower" and "Jaybeam" TH3 3 band trapped Yagi. both units installed in 1978 and still going strong, (the tower was painted and rewired last year, and a new rotator fitted).
Iv'e used W3DZZ and G5RV and other "miracle" wire antennas and thanks but no thanks, certainly on 20 and 15.
Problem is you see my back garden is only only 60ft long from the back wall of my house.
As regards linears, last year I purchased from a local amateur a Ranger 811H and it most certainly helps in pile ups NO doubt about that.
So I reckon Iv'e had good value for money out of these articles

[w2nsf]

I have neither an HF beam nor an HF amp, but I do have this one simple observation: a dB is a dB and how you get it is irrelevant.
An amp and beam will increase your effective radiated power (dB out).
A beam will also increase the directionality of your signal (dB out) and improve your reception (dB in).
Those who "poo-poo" one or two S-units don't know what they're talking about. One S-unit is frequently the difference between having and not having a successful QSO.
The only down side I can see with them is the cost, which is what's keeping me from having them. Of course, a beam is more susceptible to damage than a plain wire antenna, but we do assume it will be properly installed.
Another positive thing about using an amp is it forces you to improve your entire antenna system, especially your feedline and connectors. If these are currently deficient, they will willingly (and often pyrotechnically) demonstrate their inadequacies when loaded with a legal-limit amp.
If you have the money, buy the amp, buy the beam, use them responsibly, and have fun!
73
Jim

[cu2jt]

Quote[/b] (K1OU @ Oct. 02 2006,12:32)]....
Then again, an amp means about squat if you don't have a decent antenna.
How true !

If you can't hear them, you can't work'em. No use putting out a big signal and then not hearing the stations coming back to your CQ.

I see this happen many times on 40m, some big guys from Europe calling CQDX and I hear a couple of W6's coming back just to be drawned in the next CQDX. Pathetic.

OK, I have an amp, AL-811 with 3 x 572B tubes and it gives me 400W out. No room for any yagis on this property but I am quite satisfied with the 33ft vertical, which works great on 40m, super on 20m with the coax stub and decent on 30,17,15,12 and 10 and, would you believe, even 6m.

[cu2jt]

Quote[/b] (VE7NOT @ Sep. 30 2006,21:24)]....
My observation. I think 1w is enough for 20 and 17
....
... and my observation is that sometimes 0.25 watts is enough for 40m. At least, I have worked a guy in Detroit, who stated he was running 0.25W. OK, he did not blow my headphones off but we could accomplish a formal QSO.

[cu2jt]

As a matter of fact, a couple of well directed multi-wavelength long wire antennas gives just as much gain in certain directions as a 4-el single band yagi.

For example, a 350ft longwire antenna will have only -1.5dB less gain than a 4 element single band 20m yagi and it will give the gain in 4 directions at the same time. If ou have a big property, you can fan out 3-4 longwire antennas and cover most of the interesting directions to a fraction for the price for a yagi and rotator. If you can live with not having the front/back ratio as with the yagi, that is.

[ve2nsm]

Quote[/b] (WB2WIK @ Oct. 03 2006,11:25)]It's really not HAAT on the HF bands. That's important for VHF-UHF, because the propagation is tropospheric. With ionospheric propagation, if you can see the sky you have a shot at working DX.

The variable is how much of the sky you can see, down to what horizon; the other variable is the height of your horizontally polarized antenna above earth ground, not above sea level or above average terrain -- those really don't matter.

It's 100% true that operating from a "mountaintop" on HF is no better than operating from sea level; in fact, stations in Hawaii who often try both (like my QSO with AH6OR in Maui last night) verify that sea level is better almost all the time. My friend Dave WA6DKN operated /KH6 for a week in May and did drive to the summit of Mauna Kea at 14,000 feet using the same mobile setup he used at his beachfront condo and found absolutely no improvement in anything when operating from the mountaintop.

The TOA of your antenna is related to antenna design and height above earth ground, and nothing else. Height above sea level or above average terrain doesn't influence this.

I'd much rather have my 20m 100' above ground in a valley than 20' above ground on a mountaintop, as long as the valley wasn't so deep that I had a substantially positive horizon.

WB2WIK/6
True, I misconstrued the meaning of HAAT, I tought the average was calculated on a far less area than this.
I meant height over ground, but not only directly under the tower, but in an area of about 4 wavelenghts around the antenna, which means a diameter of only 80m on at 30MHz but almost 340m at 7MHz!

HAAT refers to a much wider area which has no effect on HF skywave propagation, only on standard 10m comms, but not skywave.