09-06-2018, 12:59 PM
Thank you Geordie for posting the circuit diagram. I am currently looking into TRF receivers and like to refer to a lot of different circuitry, but this was one to look at as I have a couple of metal cased 6K7's. At some point in the future I would like to put together something more vintage looking. With my more modern valves I am less concerned, but like the look of more vintage valves (I suppose they all are really?) in a more period setting.
Thanks Ed, I will definitely bear in mind for when I get into doing what I mentioned above, or refurb if a set comes my way. I keep quite a few things, and have built up a stock of variable capacitors. I often try to wind my own coils, but I know some are complicated. I would not likely try a wave wound, but have done such things as basket weave.
My usual forte is use of slightly newer valves in things I put together myself. I don't intend to hijack the thread, but I have currently just tested yesterday a basic setup on single frequency (648 kHz, Radio Caroline). with tuned 80 cm x 80cm frame aerial to ferrite rod tuned input to untuned EF183 pentode with manual gain control. Next a Russian miniature pentode (not rod) 6j1b-v with anode tuned circuit, then to a 6C4 triode working as an infinite impedance detector. I output to my bench audio amplifier. The MW coil on the ferrite I wound myself (as I did the frame aerial). To be honest I was amazed at the results. I think a lot of it was in the aerial and input matching, but audio seemed just as good as my usual comms receiver or transistor radio, which I use daily. There was not a lot else during the day (I only varied the tuning on ferrite rod capacitor) but as evening approached I had to back off the gain (seemed like appearance of cross mod with the higher signal level. It's seems well worth looking further into, which I will be doing. Anyway I will perhaps open a thread in the future when I have more to share.
Tracy
Thanks Ed, I will definitely bear in mind for when I get into doing what I mentioned above, or refurb if a set comes my way. I keep quite a few things, and have built up a stock of variable capacitors. I often try to wind my own coils, but I know some are complicated. I would not likely try a wave wound, but have done such things as basket weave.
My usual forte is use of slightly newer valves in things I put together myself. I don't intend to hijack the thread, but I have currently just tested yesterday a basic setup on single frequency (648 kHz, Radio Caroline). with tuned 80 cm x 80cm frame aerial to ferrite rod tuned input to untuned EF183 pentode with manual gain control. Next a Russian miniature pentode (not rod) 6j1b-v with anode tuned circuit, then to a 6C4 triode working as an infinite impedance detector. I output to my bench audio amplifier. The MW coil on the ferrite I wound myself (as I did the frame aerial). To be honest I was amazed at the results. I think a lot of it was in the aerial and input matching, but audio seemed just as good as my usual comms receiver or transistor radio, which I use daily. There was not a lot else during the day (I only varied the tuning on ferrite rod capacitor) but as evening approached I had to back off the gain (seemed like appearance of cross mod with the higher signal level. It's seems well worth looking further into, which I will be doing. Anyway I will perhaps open a thread in the future when I have more to share.
Tracy
