Amateur TV

[w5klb]

Just kinda wondering how many out there are into Amateur Television.

I am trying to get a station up at my home. Me and one other person are the only ones that I know of in my community who are attempting to do this. I live in in a city of 28K souls with about 200 hams and we are the ONLY two doing this. Is it because that it's too cost prohibative, or is because of lack of interest? #

If I could get enough interest I wouldn't mind having a amateur television repeater here and maybe a club just for guys and gals like me who like to experiment with it. But getting enough interest here may be more of a challenge than getting my station up.

I think that Amateurs should be seen and heard. I just hope that I don't cause anything to malfunction with my face being transmitted through it. #http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif #http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif #http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

[AG3Y]

There is a very large and dedicated group of ATV enthusiasts in the Baltimore Md. area. They have a complete club devoted to the subject, and run a repeater that gets wide use throughout the area.

I am not into ATV myself, but with the modern electronics that are available, it is much easier to get involved!

Here is a "quick-start" page from the BRATS ( Baltimore Radio Amateur Television Society to get you started!

http://www.bratsatv.org/atv_notes.html

Good luck and have fun !
73 from Jim AG3Y

[WA2ZDY]

The technical end of things tends to get in the way of ATV. Antennas and feedline are extremely critical, as ATV is a weak signal mode. And at 430 MHz, problems are magnified.

A big part of the problem is called "power density." (Jim is much better qualified than I am to comment on this.) But basically, the power transmitted is spread across more than 4.5 MHz. And all the cute little 1w ATV transceivers that have been around for a while are the epitome of that. One watt, with that power density question, will just about get your signal out of your back yard.

Repeaters make things better, but the technical issues and the expense make them rare.

So, maybe that's helped answer some of your questions. There's no reason not to try ATV, just realise, it's not a non-technical plug and play mode.

Good luck.

[w5lda]

Gary,,please dont air your mug on tv,,i would have to shave my dog's butt and teach him to walk backwards.

Larry kd5vsg

[AG3Y]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">A big part of the problem is called &quot;power density.&quot; #(Jim is much better qualified than I am to comment on this.) # But basically, the power transmitted is spread across more than 4.5 MHz. #And all the cute little 1w ATV transceivers that have been around for a while are the epitome of that. #One watt, with that power density question, will just about get your signal out of your back yard. #[/QUOTE]<span id='postcolor'>

I've got an interesting story to tell about that. #( I can hear you now. . . #&quot;Oh sure he has ! &quot; #)

One year we had a fire in our transmitter near Hagerstown, MD, and it was obvious that we were going to be off the air for several days if we didn't do something. #Our station's feedline was a 6 inch diameter coax hardline, but I got to thinking that there MUST be some way we could couple the RF from the exciter directly to the antenna. #Well one of the fellows from our studio/broadcast-center remembered an &quot;N&quot; to 6 inch adapter that was used ( rarely ) for testing purposes.

By multiplexing the Aural and Visual signals from the exciters into a common output stage, we were able to go on the air with a mighty 12 watts of RF ! # Of course, that was multipled by the gain of the UHF stack, but still didn't amount to much more than 200 watts ERP! #( combined over the full channel bandwidth - that's Visual Carrier, Aural Carrier, Chroma Burst, Horizontal and Vertical sync pulses and Stereo Pilot ! )

With that mighty signal #( I'll let you figure out how many dB we were down from our normal approximately quarter megawatt ! ) we were still nearly full quieting on the Hagerstown and surrounding communities cable systems! #Didn't do too good down in Winchester VA, or Cumberland MD, however ! # http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

73 from Jim AG3Y

[kd5scg]

I can't agree that all amateurs should be seen and heard. Some things just aren't pretty.

[AG3Y]

You've heard of &quot;a face made for radio&quot; , haven't you ? ? ?

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

73 , Jim

[WF7I]

In Tucson there was one guy doing ATV in the entire area of about 1 million people. I'm not sure if it's the same elsewhere, but at least there it was dead.

I agree with another poster, it seems like it's mainly plug 'n chug and not all that interesting unless you're strapping a camera to a rocket or high altitude balloon. Looking at hams look at each other is, well...not something I want to spend an evening doing!

[K9STH]

Many years ago, like around 1960 and 1961 I had a flying spot scanner and a &quot;free running&quot; 12AT7 transmitter.

I also used the transmitter along with a Motorola closed-circuit camera my senior year at Georgia Tech (1966).

Then, between 1970 and 1972 I had one of the LTV amateur television transmitters. This had a 5894 as a &quot;free running&quot; oscillator and had an input of about 50 watts. Output was probably something like 20 watts. Use the same Motorola closed-circuit camera (black and white).

Traded off the LTV transmitter (it was in a 30 inch high rack mount type cabinet and was painted two or three different shades of green) early in 1972.

I have some fairly &quot;up to date&quot; books and such on ATV. But, so far, I haven't put anything on the air since I moved into this particular house 32 years ago!

Glen, K9STH

[w5klb]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (oklahomasteel @ June 18 2004,14:26)</td></tr><tr><td id="QUOTE">Gary,,please dont air your mug on tv,,i would have to shave my dog's butt and teach him to walk backwards.

Larry kd5vsg[/QUOTE]<span id='postcolor'>
And that part of the dogs anatomy will probably be better looking! Heck it gets so bad around my house that my xyl ends up coverng up the mirrors to prevent breakage. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif #http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif #http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

Yep, I understand that ATV is not a plug and play mode. But I am NOT looking for plug and play. I am looking to learn something. And any knowledge gained from such an experiance will be well worth it.

ZDY,

4.5 MHz? I heard that it was 6Mhz. But I understand that if you plan to use a power amplifier for this mode that you can only use about 1/2 power, because of distortion, and that your amplifer better be pretty broad banded.

Still it would be kinda of neat to try this mode.

[w5klb]

Jim, AG3Y,

I have two words for you-THANK YOU!!

I am planing to email the BRATS website to a friend.

Lots of good advice.

[WA2ZDY]

WPW, you're correct - sort of. The NTSC standard channel bandwidth is 6 MHz. The video signal with vestigial sideband is around 4.5 MHz.

As I sit here and think about it, I remember one of the &quot;economy&quot; ATV rigs sold in the last 15 years or so wasn't even vestigial sideband. I had two full sidebands. There's MORE power wasted in the power density equation.

Great story Jim. At least you got on the air, but you also pretty well confirmed my version too. That makes me feel good, being you're a professional in the field. And me, I'm just a ham. Hmmmm . . .

We had ATV equipment at my HS radio club in the mid 70's, including one of those MONSTER cameras that was surplus from CBS I think. What a treat THAT was. We never made any contacts. Nobody else was on. In fact, we had a really good and well equipped ham club in my HS. Those were the days.

[K6UEY]

KD5WPW,
Gary, yes you are right the TV width is just under 6 MHZ that includes the video and the 4.5 MHZ FM Audio sub carrier.There are quite a few running TV or at least here on the West coast and it is my understanding it is popular in the mid west.There are a series of TV repeaters from Arizona into Nevada ,to Los Angeles and there was a link to Northerm California,until a storm took down the antennas on Mt Diablo at the northern end of the link.
There was an E-mail Reflector for TV out of Florida,but I haven't seen it for several months.
My suggestion is to contact Henry- KB9FO ask him to point you in a direction,for what you want to do, he is very knowledgeable and helpful....Lots of Luck...73, ORV
PS-
Keep in mind for later after you are up and running on analog TV, going digital .....ENJOY... http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

[KG4WRA]

If I could afford the equipment, I would love to try stuff like that. But like you, I don't know of anyone in my area who likes to do that sort of stuff. I'm sure there are several, but I just don't know about them.

[KC5SAS]

Another good source of informatin can be from the various email lists and message Groups available. Check out this Yahoo Group as an example of what you can find- http://finance.groups.yahoo.com/group/Ham-ATV/
Good luck,
Steve