Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Sencore SG165 rf problem
#1

I have a sencore sg165 analyzer that came with some of the usual problems I have read about online. The am/fm tuning cap shaft was broke. I repaired it and have accurate am freq. readings but no fm readings.
I checked the tr314 tr 315 out of circuit and they test good.
Any help with what to check next is appreciated. Also all the other settings sine, square wave and sweep etc. appear to be working correctly. Thanks for help.
#2

Have you looked with a scope? It is fairly small output.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#3

Thanks Mike, I did have it hooked to scope when checking the sine/ square wave ,not the fm frequency. With the tuning shaft broke after fixing , I was using an B&k 1gig frequency counter to test the fm frequency. The am is reading fine. I will have to reinstall the main rf board and transistors to get it back to look at on scope. I would think the fm should read on the frequency counter. The counter reads all the fm frequencies on my leader lsg 215a signal generator.
Before removing the main RF board I did check the volts from ground to base of the tr315. It read -12volts. according to manual oscillator tr314 runs only when there is 12v+ at base of tr315 turning it on and supplying emitter current to tr314. I don't know why it had 12v- at base. Thats why I thought I had a bad tr315 transistor. The molex plug to RF board from the power supply board have both -12v and 12v+. I will try to get the schematic downloaded and put up here.

http://s1336.photobucket.com/user/220koh...c.jpg.html
http://s1336.photobucket.com/user/220koh...b.jpg.html
Here is the rf section of the manual.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Gilfillan Brothers Car Radio?
There is a Mission Bell model 19/19A that could be what you’re looking for, Riders vol 4. It has the tube line-up of: 0Z...Joe Rossi — 05:01 PM
Looking for verification of correct schematic.
Definitely 870044RossH — 01:12 PM
12' Philco
Wonder if the chassis was big too.daveone23 — 12:38 PM
Philco 38-2 Automatic Tuning
Hi Ron, I have sent Radio Daze my concerns with the dial so I guess we will see. They used my original to make the repro...dconant — 12:27 PM
Hickok AC51 tube tester
How does the  5W4 and 83 tube filaments get fed?martinj — 12:25 PM
462ron
Hi Dan, your original dial appears to be lighter, easier to allow light through. My original is similar except it’s crac...462ron — 12:07 PM
Philco 38-2 Automatic Tuning
I received my new 38-2 dial. I'm a little disappointed. As you can see in the picture the blues have a white shadow. The...dconant — 11:13 AM
Philco 38-2 Low Volume
I have been playing my 38-2 for a while now and it is doing very well. I did have to replace the 6A8 (osc) as it develop...dconant — 11:03 AM
Philco Speaker Spider
Hello, Does anyone with a 3 D printer make the spiders for those old Philco speakers? That might be a good idea for some...dconant — 09:41 AM
Philco 16B Parts
Hello, I'm looking to buy a 16B but I'm not so sure of what I am looking at. First as seen from the picture it looks lik...dconant — 09:17 AM

[-]
Who's Online
There are currently 2751 online users. [Complete List]
» 2 Member(s) | 2749 Guest(s)
AvatarAvatar

>