Heathkit 6 transistor AM Radio Dilemma & Update on the RCA Strato-World 3-BX-671
Жүктеу.....
Пікірлер: 15
@ScoutCrafter26 күн бұрын
That’s a tough call Fred- The overall condition of the radio looks good but maybe someone tried hooking up AC to the set. Summer is a good time to have an AC shop! 😂👍🇺🇸
@ko2fjb
26 күн бұрын
Well I'm like you so I'll probably take on the challenge as long as I can source the parts. Yes, I have central air so the shop is very pleasant. I'm here in North Jersey so our temps are probably very close.
@KnightT6026 күн бұрын
If it was mine, I’d be forced to take on the challenge. Sometimes it’s about more than money. As far as the transistors are concerned I can offer a few thoughts. 1) Salvage them from an old pocket transistor radio. 2) Purchase NOS Soviet transistors off of eBay. They have really dried up since the war broke out in Ukraine, but there are still several sources. 3) I’ve often replaced germanium transistors with silicon and found rebiasing unnecessary. Even if it is, if you begin at the output stage it should be possibly to come up with suitable resistor values by doing a little bit of experimenting. 4) Replace the audio stage with an LM-386 or something similar. In the end it’s your decision. It’s your radio, your money and your time.
@ko2fjb
26 күн бұрын
I will probably take it on as a project. I'm looking to cross reference the bad transistors to Russian . As I'm more of a traditionalist I probably won't use an lm386. The output shouldn't be too much of an issue.
@michaelmacdonald340824 күн бұрын
It sounds like somebody connected the power supply wrong.
@michaelmacdonald340824 күн бұрын
Wait for a donor to come along.
@sefarkas026 күн бұрын
Briefly looked at the schematic. since the currents are so low all but the audio stages would need rebiasing. Specifically R19. I have no idea what an R240 transistors is. maybe floor sweepings from Raytheon?
@ko2fjb
26 күн бұрын
LOL , who knows what R250 or R251 could be other than PNP, there is no reference in the construction manual. I like a challenge so if I can source suitable parts I'll move forward.
@hestheMaster23 күн бұрын
The R250 audio output transistors were probably a 2N214 or sub. The R251 was a driver and probably a 2N213 sub. All NPN and a Germanium design. Try finding good old NTE103 to replace those Germanium ones. Best guess IMHO.
@ko2fjb
23 күн бұрын
Awesome, thank you, I could not find any reference to R250 & 251 transistors.
@hestheMaster
23 күн бұрын
Just trying to find some compatible NPN transies. NTE 103 aren't too cheap like most Silicon ones are.
@romjone480123 күн бұрын
I would restore it. It is a fantastic radio. My radio didn't have knobs for it. I had to purchase another radio to recast new knobs. The knobs are very expensive and hard to get. I ended up with three XR-2 radios. Fix it!
@ko2fjb
23 күн бұрын
Yea, I've pretty much decided to restore it. I still have to test all the transformers and source parts before I move forward. Stay tuned in for more details.
@romjone480117 күн бұрын
Restore it. Take the challenge!
@ko2fjb
17 күн бұрын
LOL, it's funny, I decided yesterday to tackle it I just finished going through the radio to make a parts order. Hopefully a get a quick video out by Sunday this weekend so stay tuned.🙂
Пікірлер: 15
That’s a tough call Fred- The overall condition of the radio looks good but maybe someone tried hooking up AC to the set. Summer is a good time to have an AC shop! 😂👍🇺🇸
@ko2fjb
26 күн бұрын
Well I'm like you so I'll probably take on the challenge as long as I can source the parts. Yes, I have central air so the shop is very pleasant. I'm here in North Jersey so our temps are probably very close.
If it was mine, I’d be forced to take on the challenge. Sometimes it’s about more than money. As far as the transistors are concerned I can offer a few thoughts. 1) Salvage them from an old pocket transistor radio. 2) Purchase NOS Soviet transistors off of eBay. They have really dried up since the war broke out in Ukraine, but there are still several sources. 3) I’ve often replaced germanium transistors with silicon and found rebiasing unnecessary. Even if it is, if you begin at the output stage it should be possibly to come up with suitable resistor values by doing a little bit of experimenting. 4) Replace the audio stage with an LM-386 or something similar. In the end it’s your decision. It’s your radio, your money and your time.
@ko2fjb
26 күн бұрын
I will probably take it on as a project. I'm looking to cross reference the bad transistors to Russian . As I'm more of a traditionalist I probably won't use an lm386. The output shouldn't be too much of an issue.
It sounds like somebody connected the power supply wrong.
Wait for a donor to come along.
Briefly looked at the schematic. since the currents are so low all but the audio stages would need rebiasing. Specifically R19. I have no idea what an R240 transistors is. maybe floor sweepings from Raytheon?
@ko2fjb
26 күн бұрын
LOL , who knows what R250 or R251 could be other than PNP, there is no reference in the construction manual. I like a challenge so if I can source suitable parts I'll move forward.
The R250 audio output transistors were probably a 2N214 or sub. The R251 was a driver and probably a 2N213 sub. All NPN and a Germanium design. Try finding good old NTE103 to replace those Germanium ones. Best guess IMHO.
@ko2fjb
23 күн бұрын
Awesome, thank you, I could not find any reference to R250 & 251 transistors.
@hestheMaster
23 күн бұрын
Just trying to find some compatible NPN transies. NTE 103 aren't too cheap like most Silicon ones are.
I would restore it. It is a fantastic radio. My radio didn't have knobs for it. I had to purchase another radio to recast new knobs. The knobs are very expensive and hard to get. I ended up with three XR-2 radios. Fix it!
@ko2fjb
23 күн бұрын
Yea, I've pretty much decided to restore it. I still have to test all the transformers and source parts before I move forward. Stay tuned in for more details.
Restore it. Take the challenge!
@ko2fjb
17 күн бұрын
LOL, it's funny, I decided yesterday to tackle it I just finished going through the radio to make a parts order. Hopefully a get a quick video out by Sunday this weekend so stay tuned.🙂