01-07-2019, 10:29 PM
Thanks, Terry. I actually got the radio from one of our club members. He has a basement FILLED with radios, mostly 1920's sets. And I mean FILLED. There's just a narrow pathway through the maze. He was looking to thin the herd, and had two of these model 206's. One was a farm / battery set, and I got this one. The cabinet is pretty rough. I've been clamping and gluing the last 3 nights, trying to take care of the water damage delamination.
Alas, this one was missing its original speaker. Gary at PTOTP had an 8 1/4" RCA speaker with a 1200 ohm field and an output transformer attached that I've been using. He had an original AK 4 prong speaker plug too, which helped. The only thing this speaker doesn't have is the hum bucking coil that was attached to the original AK speaker. It's CK1 on the schematic. It that critical and if so, what could be used in place of it?
I double checked C6, C9, and C10 and they appear to be correct. The .03 mfd cap goes to #24 on T3, which is at the 7 o'clock position:
I replaced a FEW of the original fossilized rubber coated wire. I am doing my best not to disturb them, as they still look good for the most part and I'd like to avoid having to totally rewire the set. I did a more thorough resistor check tonight, some are very small value, like 1 ohm, even a .5 ohm I saw.
Tonight I tried replacing C2 (2200 mmfd, I replaced with a .0022 mfd), C3 (25 mmfd, I replaced with a 25 pf), and R3, the 65K ohm resistor. Mine was reading 109K. I had the set upside down and when I turned it on, all I got was motorboating. So I turned the set right side up, turned it back on and still got motorboating, until I pushed down on the grid cap of the #58 IF tube (the infamous culprit). Then the motorboating stopped and I started to receive the same two stations I was, although they are still very noisy and sound distant. They are strong stations, yet you have to really fish around to find them and get them to come in somewhat clear.
Something is holding back the reception from coming through loud and clear. I'm getting very little if any response on all of the grid caps when I touch them with my finger, except for the 58 IF...when I touch that grid cap, the set goes silent (station reception goes away). Going to have to do some signal tracing. Do you have any ideas on what to zero in on?
PS: (I did see that video and loved it. You might enjoy this: https://www.youtube.com/watch?v=89tg6fonbNQ)
Alas, this one was missing its original speaker. Gary at PTOTP had an 8 1/4" RCA speaker with a 1200 ohm field and an output transformer attached that I've been using. He had an original AK 4 prong speaker plug too, which helped. The only thing this speaker doesn't have is the hum bucking coil that was attached to the original AK speaker. It's CK1 on the schematic. It that critical and if so, what could be used in place of it?
I double checked C6, C9, and C10 and they appear to be correct. The .03 mfd cap goes to #24 on T3, which is at the 7 o'clock position:
I replaced a FEW of the original fossilized rubber coated wire. I am doing my best not to disturb them, as they still look good for the most part and I'd like to avoid having to totally rewire the set. I did a more thorough resistor check tonight, some are very small value, like 1 ohm, even a .5 ohm I saw.
Tonight I tried replacing C2 (2200 mmfd, I replaced with a .0022 mfd), C3 (25 mmfd, I replaced with a 25 pf), and R3, the 65K ohm resistor. Mine was reading 109K. I had the set upside down and when I turned it on, all I got was motorboating. So I turned the set right side up, turned it back on and still got motorboating, until I pushed down on the grid cap of the #58 IF tube (the infamous culprit). Then the motorboating stopped and I started to receive the same two stations I was, although they are still very noisy and sound distant. They are strong stations, yet you have to really fish around to find them and get them to come in somewhat clear.
Something is holding back the reception from coming through loud and clear. I'm getting very little if any response on all of the grid caps when I touch them with my finger, except for the 58 IF...when I touch that grid cap, the set goes silent (station reception goes away). Going to have to do some signal tracing. Do you have any ideas on what to zero in on?
PS: (I did see that video and loved it. You might enjoy this: https://www.youtube.com/watch?v=89tg6fonbNQ)
Greg V.
West Bend, WI
Member WARCI.org
