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

Philco 38-690 electronics restoration.
#97

Still some ails that plague it. One is this switch, the BC band secondary solders to the switch contact that is unreliable. No good way to reach it.

Then there's an open coil primary at the 2nd band, which I think I'll leave be as it is the police etc band, not much there anyway. Other bands I aligned.

Then the dial...am not sure as to it being exact same with internal ring, as in 37-116 deluxe, as then it means the inner ring is missing and someone riveted a piece of aluminum to the opposite of the stub that used to hold the ring and now he two are used to hold the dial which otherwise is good, but it slips and not held reliably.

Then there was this hum. Pretty pronounced. Right across the bass field coil I saw a pretty large ripple. I tried caps tono result. Then I started tacing it and traced to the power amp 6F6 input. That traced to the tuner output, the second audio 6N7, metal case. I realized the capacitor that is the output of it was hidden and I didn't restuff it. Fixed it, again to no result. So I cannibalized my 37-116 chassis with a glass 6N7G and....the hum went down a lot.
Then I looked at the second 37-116 chassis and it had a metal 6N7, same as I have, and after the change the hum was practically gone.
That was the tube!!!! The ripp!e on the scope also went way down.
The tube did test well - I tested all of them.

Well, at least some good news for today.

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.


Messages In This Thread
Philco 38-690 electronics restoration. - by morzh - 04-12-2017, 08:19 PM
RE: Philco 38-690 electronics restoration. - by morzh - 11-26-2017, 09:47 PM



Users browsing this thread: 12 Guest(s)
[-]
Recent Posts
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM
Hickok AC51 tube tester
Absolutely no one is going to reverse engineer that circuit. Even the iron core is missing.RodB — 10:37 AM
IF can wire size and Rubber mounts?
Thanks to both members for your help regarding wire and tuner mtg supports. regards--Johngeorgetownjohn — 09:33 AM
Hickok AC51 tube tester
Note that no power cord, power switch, or power transformer switch are shown. That (along with my experience with full s...DaleHCook — 07:09 AM
IF can wire size and Rubber mounts?
A pair of wire strippers can give you an idea of what the existing gauge of the wire leads are in the IF can, I think it...Arran — 06:07 AM
My last cabinet for this year
Hello Dan, That is really beautiful what great looking radio you have ! I have friends who live in Calgary and the wea...radiorich — 01:51 AM

[-]
Who's Online
There are currently no members online.

>