I picked up a nice XR-1 on eBay. This was Heathkit's first transistor radio kit I believe. I changed out the electrolytics and fired it up using a Heathkit Power supply set at 9V. I get low volume, i.e. only get 2 or 3 strong stations and the volume is all the way up. I did the standard tracing. I believe I narrowed down an issue but need to understand what is typical since this is my first transistor radio rework.
Here is the schematic for reference:
http://louhaskell.com/data/heathkit-xr1-schematic.jpg
I get about 1.5V peak-to-peak of nice modulated IF at the collector of the 2nd IF transistor, pin 3 of the last IF transformer. But I only get about 0.1 - 0.2V at pin 1, which is connected to the top of the volume control.
I measured the winding and got 1.5 ohms on the primary and 5 ohms on the secondary of xfrmr 52-13. Also, moving the slug made very little difference in the peaking of the IF can. Strange I thought. I removed the xfrmr and took it apart since it has the diode and caps inside. The diode is good, the caps seem good?? No loose connections. Just connecting an RF generator at 455kc across the primary and putting a 2.5K resistor across the secondary gives me the same results on a little test bench. SO not sure what is up with this thing.
So.. some questions:
1. Is 1.5V at the collector of the 2nd IF transistor about as much as can be expected?
2. Given the resistance measurements of the primary and secondary, does the xfmr seem like it should step DOWN the voltage by a factor of 5? (true, it has to overcome the 0.2V junction of the diode but I included that in the calculation.
3. Is 0.2V on the volume control good and I should understand why the amplifier stage is not stronger?

Thanks,
Lou

What are the DC voltages on that transistor?

Don't recall exactly, but they are within 0.2V of the schematic specs. Nothing that raised a flag for me. I do not have a transistor tester so I do not know of any leakage issues or what the gain of the transistor is.
I do recall that that stage (the 2N254) had a gain of only perhaps 2 to 3 which I thought was somewhat bogus.

Assuming the audio section is properly working, (inject a signal) I'd check every resistor forward up to the antenna for proper value, as well as making sure none of the small value caps haven't gone leaky.
If nothing comes from that, try a new transistor, any old NPN replacement would work.
Sometimes they go leaky/tin whiskers, and since they're plug-in, the socket can corrode too.

Chek voltages at 3 AF transistors. Chek difference of 0,1 V betwenn C-B .
Try touse a different speaker.

Hello Lou,

Have had a few transistor sets in the past couple years with bad internal IFT caps---two were mid-late fifties with the silver mica wafers in base & two were mid '60's identical Philco sets with tubular ceramics... Other than one which I damaged windings while trying to disable the internal mica wafer, the remaining three I was able to repair by simply parallelling internal with a 365 pF variable to determine what value was needed to get peak performance with slug mid-travel, then installing outboard fixed ceramic caps on PCB bottom... Symptoms were exactly as you described... Try it across pins 3 & 6 of suspect IFT and see... Good luck...

John

Yes, I had a similar problem with a Sonic radio from around 1958; the IF transformers would not peak. Our old silver migration/tarnished contact problem is showing up in transistor sets now.

The short square IF transformers in those early sets are very difficult to repair.