IF can wanted

[K7SGJ]

George, how did this turn out, or did it yet?

[w2amr]

George, how did this turn out, or did it yet?

I drilled out the rivet that holds the mica wafers together in the bottom of the IF. Then I took them out, reassembled the can, put it back on the chassis, and soldered the wires back on. Then I took a guess at the value and tacked a 120 PF cap across each coil lead. It receives, but not very well. I just have to find the right value caps to replace the micas.

[K7SGJ]

I have a bag full of Arco trimmers that might help you out. I can send you one of each if you like. If you find one that works, you could leave it in, or measure it and put in a fixed value that is close, and tweak the coil a bit. The nice thing about leaving the trimmer in, is that you can peak it at values that standard value fixed caps are not available in. Although I have a bunch of these, I think there are just 8 or 9 different values. Follow this link to find actual values. The ones I have are 400, 402, 407, 408, 469, 4613, 4614, and 4615. Shirley, one of them should get you there. Between the coil setting and capacitor setting, you should be able to get resonance with out too much trouble. The linked site is a bit hard to read, but you can get some idea of what's what. I'm sure there are sites with better resolution of the Arco page. Good luck, and let me know if you want me to drop these things in an envelope for you.

[w2amr]

I have a bag full of Arco trimmers that might help you out. I can send you one of each if you like. If you find one that works, you could leave it in, or measure it and put in a fixed value that is close, and tweak the coil a bit. The nice thing about leaving the trimmer in, is that you can peak it at values that standard value fixed caps are not available in. Although I have a bunch of these, I think there are just 8 or 9 different values. Follow this link to find actual values. The ones I have are 400, 402, 407, 408, 469, 4613, 4614, and 4615. Shirley, one of them should get you there. Between the coil setting and capacitor setting, you should be able to get resonance with out too much trouble. The linked site is a bit hard to read, but you can get some idea of what's what. I'm sure there are sites with better resolution of the Arco page. Good luck, and let me know if you want me to drop these things in an envelope for you.

That's a great idea Ed. I think I may have some of those in the garage. I'll look for them tomorrow and let you know. Thanks.

[w2amr]

Good news guys, I found two arco #460 trimmers. internets say the values are 25-115 PF. I'll try them this weekend.

[w2amr]

I put the trimmers in and they worked fine. Trouble is, the radio only hears very strong signals. I must have issues somewhere else.

[N8YX]

I put the trimmers in and they worked fine. Trouble is, the radio only hears very strong signals. I must have issues somewhere else.

Bypass and/or coupling caps in the RF and IF amp stages? Could have more micas going bad, and any Orange Drops under that chassis are immediately suspect.

[w2amr]

Bypass and/or coupling caps in the RF and IF amp stages? Could have more micas going bad, and any Orange Drops under that chassis are immediately suspect.

Could be. I think the next step is to check voltages at the tube sockets. But, I'm getting close Fred.

[K7SGJ]

Signal injection at this point is a good way to go on a receiver with the symptoms you have there, especially if the DC voltages are close. If you don't have a signal generator, often a noise generator can be helpful, and are easily and quickly built. Of course a grid dip meter can be used, as well as a DDs if you have one of those around. Measuring with a VTVM or DVM on a low ac scale, you can get an idea of stage gain. I would assume if you were to get 10db or better at each stage, it would be safe to assume it's working okay. With your current problem, I would try to look around the RF amp stage. If you tune to a signal you can hear, then that can be used to measure stage gain and even how well the RF amp is doing. Good luck. It looks like the final fix is just over the horizon, which reminds me of a story about the Fugowi Indians, but I digress...........

[w2amr]

Signal injection at this point is a good way to go on a receiver with the symptoms you have there, especially if the DC voltages are close. If you don't have a signal generator, often a noise generator can be helpful, and are easily and quickly built. Of course a grid dip meter can be used, as well as a DDs if you have one of those around. Measuring with a VTVM or DVM on a low ac scale, you can get an idea of stage gain. I would assume if you were to get 10db or better at each stage, it would be safe to assume it's working okay. With your current problem, I would try to look around the RF amp stage. If you tune to a signal you can hear, then that can be used to measure stage gain and even how well the RF amp is doing. Good luck. It looks like the final fix is just over the horizon, which reminds me of a story about the Fugowi Indians, but I digress...........

Ok Ed TNX.