thebes Posted February 14, 2016 Share Posted February 14, 2016 Using my limited toy budget I've started playing around with a Dyanco FM# tuner. Per info from the Van Alstine site, I've replaced four caps, and increased the values on two of them. I've also tested the tubes, hooked everything up, and started the alignment process. I'm having two issues, the volume drops off after awhile, so I'm figuring the power supply can should be replaced, and secondly there's one alignment procedure using a mutlimetter that I don't really understand. First the multican, which is 40/40/20/20 350v. I was thinking of saving the cost of a can and just putting the cans underneath but here is only an inch of clearance in the case, so a very tight fit indeed. Is there some other method besides can stuffing, which I tried once and failed at, so I could mount those caps on top? Second aligning the discriminator, (I now, I know, I didn't make up the word) Here's a link to the manual: http://www.curcioaudio.com/Dyna%20FM-3%20Mnl.pdf On page 18 there is a procedure using a mutlimeter where I can bypass steps 14 through through 23 It's Step 24 in the manual. I have no problem getting the top slug to -11volts (minus 9 volts in the online manual, minus 11v in my manual that came with the tuner. However, I can't seem to zero out the lower slug. The radio station comes back into play and sounds loudest at around ,850 millivolts (I think that's what I'm reading) but I can't seem to zero it out. I'm using a digital meter that automatically adjusts, so should I be setting it's DC parameters somehow to make this work? Quote Link to comment Share on other sites More sharing options...
Jim Naseum Posted February 15, 2016 Share Posted February 15, 2016 On page 18 there is a procedure using a mutlimeter where I can bypass steps 14 through through 23 It's Step 24 in the manual. The instructions in 24 are for use with a Vacuum Tube Volt Meter (VTVM). A digital multimeter will probably not work for 24. This is because a VTVM has a super high input impedance that will not load down a high impedance tube load. A VTVM is an older, very large instrument. Do you have one? Quote Link to comment Share on other sites More sharing options...
thebes Posted February 15, 2016 Author Share Posted February 15, 2016 Oh, that's what they were talking about. I got a Radio Shack thingie that looks a lot like that but I think it's just an analogue voltmeter. Looks like I'll have to do it the hard way and poke more sharp instruments into live wires. Great. Can't wait. What could possibly go wrong that hasn't gone wrong before. Trepidation Thebes Quote Link to comment Share on other sites More sharing options...
Jim Naseum Posted February 15, 2016 Share Posted February 15, 2016 Oh, that's what they were talking about. I got a Radio Shack thingie that looks a lot like that but I think it's just an analogue voltmeter. Looks like I'll have to do it the hard way and poke more sharp instruments into live wires. Great. Can't wait. What could possibly go wrong that hasn't gone wrong before. Trepidation Thebes If you bought the RS meter in the last 30 years or so, it's probably not a Vacuum Tube Volt Meter! Tuner alignment might be one of the last real audio purposes for a VTVM. GOOD LUCK ON THE LONGER SET OF STEPS! Sent from my SM-T330NU using Tapatalk Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 16, 2016 Share Posted February 16, 2016 Good grief Thebes my feeling are hurt....no cal;l for help. Quote Link to comment Share on other sites More sharing options...
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