Recent content by TubeJunkie

No the tuning meters do not move

I’m looking at a BK Precision 4040 sweep generator. Any reason I shouldn’t go with this unit?

Didn’t find any loose wires. I turned L1 screw on end of AM bar that’s mounted on the back panel. Didn’t make it any better. I’ll look at the RF amplifier stage. Thanks again! Should I start pulling capacitors out of the AM section and test them out of circuit? Or, where should I look?

Right on guys! I’m looking at buying a sweep generator. Just not sure what model and specs to buy. Are the cheap new China versions good? Are there any other test equipment I would need for tuner alignments? I’ve been wanting to dive into tuner alignments for years. I’ll look for a loose wire...

Thanks for the info. For test equipment I have an Eico 377 Audio Generator, and a Sony/Tektronix 305 Oscilloscope. Will these two units be suitable for AM alignment? I’ve repaired hundreds of vintage Audio Units including guitar amps, but honestly, Radio is my weakest point in skills.

Yes. I have an antenna connected.

My Fisher RS-2010 has very weak AM tuner. It barely picks up one station. The FM is fine, but has an occasional pop, just one pop at a time . I’ve looked at the schematic and took some voltage readings. IC05 - All pins have the correct voltage except pin 15 is 3.2 mvDC, should be 133 mvDC. And...

Anyone have a service manual for this ? Is there anybody out there? lol

Hello! I have a Lafayette LR-221. I'm in need of a service manual for it. One of the right channel fuses was missing. Also noticed one of the bias adjustment pots (RV501) is broken. Never had this model before, but I hear they sound quite nice. Any help is greatly appreciated. Thanks

Found this. Which should work. The 4th terminal is the center tap. The shaft is too short, so I’d have to use a flat screwdriver to adjust the pitch. I’d still like to find the correct pot with longer , knurled shaft...

Hello. I have an Akai GX-635D reel to reel machine, with a broken pitch control pot. The shaft is broken clean off. This is a 1 kOhm b pot with a center tap. Three terminals on bottom like a standard pot, but with a center tap on top of pot. I’ve looked online and can’t find one like this one...

Before I found the bad capacitor C418, I had already replaced C417 and a few other out of spec caps in that channel. Which brought down the high DC center voltage in that channel. So then, I started puling caps in the opposite channel, and I found C417 was open, No meter reading. Thanks for...

UPDATE: It's fixed! I found a failed capacitor. C418. 220uf - 10v. Luxon brand. Never seen this brand. I researched Luxon brand capacitors, and seems they have a high failure rate. Hit or miss. Anyway, The center voltage is around 50 mvDC per channel. And the bias is set to 15 mvDC per channel...

Bridge mode is off. No change when switching Soft Clipping or LAB input. I started pulling and testing transistors out of circuit, haven't found any bad yet. I also pulled some electrolytic caps and replaced the ones that were out of spec. Now I have -0.082 mvDC center voltage on left channel...