Tx with sweep valves
 

I'm on the lookout here for some circuits that use sweep valves for transmitter on 160 metres. Something very simple for CW.
Using PL500 / PL504. There doesn't seem to be much out there regards using TV valves for other purposes.
Any help or directions appreciated.
Ta

Re: Tx with sweep valves
 

Hi

As far as I know, usual circuits for valve transmitters can be used. Obviously heater voltages are different. The PL509 is a popular choice. Don't know what the power limit is for 160 in Spain, but in the UK, just one of those devices is more than enough for CW/AM

73s

Aub

Re: Tx with sweep valves
 

These are lower voltage/higher current devices than the usual RF power valves, so you'll need some different values in your Pi-network to load them up appropriately.

I believe Steve Webb of CobWebb antenna fame published a sweep toob linear of very light weight using a voltage-multiplier/rectifier mains transformerless PSU. safety isolation was by RF transformers. G3TXQ.

There is also the 'Frinear' with 4x PL519 by PA0FRI

Might be worth looking at, but I'd use a mains transformer.

David

Re: Tx with sweep valves
 

There's the KW-160 AM/CW transmitter, that uses a PL81 or 82 PA valve. I own one and have the circuit details if you can't find info on google search.

73

Roger/G3VKM

Re: Tx with sweep valves
 

Great , thanks for the reply's, yeah 10 watts here but not full 1.8 to 2.0mhz i,m afraid , not sure why but i probably can find out . failing that a CW Tx for 80. I have an old valve TV that's bit the dust so looking at what valves are in it , obviously the power supply will be very useful as well.

Re: Tx with sweep valves
 

Yes a PL81 or a PL36 should be a handy PA and there should still be a lot of them about.

Re: Tx with sweep valves
 

Here's a single-band PL509 PA from an interesting site
http://g4oep.epizy.com/pl509/pl509.htm
- Peter G3PIJ

Re: Tx with sweep valves
 

Why reinvent the wheel? 807s are still available cheaply enough!

Re: Tx with sweep valves
 

i have found a design , simple and interesting and now on the continued look out .
On the point of a PA / Linear i vaguely remember there was a design many years ago late 50s early 60s that was single or double valve i think in PW, it went through a few alterations over time and was using TV sweep valve , it was well known but slightly controversial i think . I think the last update was about 1966, i dont think it was G3OGR though, not sure.

Re: Tx with sweep valves
 

Re. post #3, Steve Webb's amplifier was called the Loudenboomer. He sold it as a commercial product starting around 1989 or 1990. I don't know if he ever published the design. I presume that the schematic was in the manual. The company was called S.R.W. Communications.

This was not first product to be named "Loudenboomer". Hallicrafters and Radio Industries also used it. This can cloud the results of a Google search.

Re: Tx with sweep valves
 

I have seen circuits that use almost every sweep tube available here in the U.S.

You might try looking for 1940-60's QST magazines (I know they had Spanish Ed.), and ARRL Handbooks.