Topband: Good valve homebrew rig
Hi Annas Having built several Transmitters and Receivers, Valve ones are SO much simpler (less stages required) . . . and they usually work straight away ! (unlike Transistor ones, where there's often issues to sort out). Plus no PCBs needed, all the components just hang off the Valve bases, mounted on a chassis. A valve CW Transmitter for 160m is VERY simple . . . the VFO is on the signal frequency, and just two valves will give you ten watts - ECF80 VFO/Buffer, 5763 PA. Add a 6146 or 807 and you will have 100 watts input (80 watts output, as Class C) If you want to make Transceiver, then you will have to have a VFO on a different frequency and Mix (so the Receiver is a Superhet) . . . but the advantage with 160m is that you can have Single Conversion from 455 kHz, so it's easy to make a stable VFO around 2.3 MHz. You'd just need to find a nice cheap second-hand 455 kHz CW Filter . . . copy some of the Receiver stages circuitry from any Valve Rx (R4B, FR400, etc) . . . so something like a 6BW6 RF stage, 6BE6 Mixer, a couple of 6BA6 IF amps, and an ECL86 Audio Preamp/Output valve. Plus a 12AT7 as a Carrier Osc and VFO. On Tx you simply use most of the same circuits in reverse, with a similar output stage as outlined for the Tx above. I built a few SSB Transceivers in the 70s using that kind of circuitry . . . but a CW one is simpler as you don't need a Mic Amp or Balanced Modulator, and you don't lose any Tx signal through the Crystal Filter (as you'd bypass it) 73 Roger G3YRO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Good valve homebrew rig
Eric lives about 15 miles from me, I’ve seen these in person, pictures can’t begin to tell the story !!! Sent from my iPad > On Dec 8, 2020, at 7:01 PM, Tim Shoppa wrote: > > NO3M has done some truly top-notch work with tube transmitters and I've > worked him using several of his "vintage homebrew" rigs on 160M. > > They are BEAUTIFUL ! Check out some pics: > http://no3m.net/vintage/160m-1928-mopa/ > > Tim N3QE > >> On Tue, Dec 8, 2020 at 4:02 PM Annas Alamudi >> wrote: >> >> Hi! >> >> I was wondering if anyone has a schematic for a good homebrew 160m CW >> transceiver, using ideally valve instead of transistors. >> >> Was hoping to build one during my next annual leave in February! >> >> Thanks! >> >> Annas >> M0GQA >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Good valve homebrew rig
NO3M has done some truly top-notch work with tube transmitters and I've worked him using several of his "vintage homebrew" rigs on 160M. They are BEAUTIFUL ! Check out some pics: http://no3m.net/vintage/160m-1928-mopa/ Tim N3QE On Tue, Dec 8, 2020 at 4:02 PM Annas Alamudi wrote: > Hi! > > I was wondering if anyone has a schematic for a good homebrew 160m CW > transceiver, using ideally valve instead of transistors. > > Was hoping to build one during my next annual leave in February! > > Thanks! > > Annas > M0GQA > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Good valve homebrew rig
Are you sure you want to homebrew a vacuum tube _transceiver?_ How about starting with a separate transmitter and receiver? A tube CW transmitter for 160 is certainly feasible. A transceiver is too in theory at least, but kind of a tall order. If you pull that off, you'll certainly have my unending admiration, but I for one can't recommend anything. A transmitter is different. What power level do you have in mind? 73 Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Good valve homebrew rig
Hi! I was wondering if anyone has a schematic for a good homebrew 160m CW transceiver, using ideally valve instead of transistors. Was hoping to build one during my next annual leave in February! Thanks! Annas M0GQA _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
