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

Philco 45 - One Last Problem
#1

I finished the re-capping including the tone control block, but it still has the same problem before the re-cap job, ie. volume/reception is near dead.

Originally the radio played well until for a couple of days the volume started to die until the radio went mute except for some light static. I can now take an adjustment stick (plastic stick with metal tips) and tap the 6A7 grid cap and get perfect volume and reception. I can trace the grid cap wire and tap connection at the bandswitch... perfect volume reception, and all the way to first connection of the wave trap. tap again, and get the same result... perfect volume and reception.

I know I'm almost there..... Can someone give me a starting place to determine fix for this condition?

Thanks,
Britt Abbott
#2

Start checking solder joints. You may very well have a "cold" solder joint somewhere in the front end of your set. And it may or may not be one of the solder joints you made - it could be a joint you did not touch.

Replace the 6A7 with a known good one also.

--
Ron Ramirez
Ferdinand IN
#3

Thanks Ron, I did try replacing the 6A7, but it had the same problem. I've tinkered with it some more since my last post, checking resistors, micas, etc.
I starting twisting on the antenae fahnestock clip on the exterior of the chassis and the sound came in bright and clear. Is this antenae clip suppose to be isolated from the chassis (ground)?? The clip appears to be mounted on a fiber washer top and bottom of chassis to isolate it. I'll also check the solder joints from the band switch to wave trap to antenae clip.

Also, while I've got your attention, I'm getting a loud buzz in the higher end of the broadcast band above 90. Can you give me a starting point?

Thanks,
Britt Abbott
#4

Yes, the antenna clip MUST be isolated from ground, else you would receive no signals! The rivet which holds the clip to the solder terminal under the chassis (on the underside of the fibre washer) may have come loose. A small screw and nut in place of the rivet will fix that.

Can't really help you on the buzzing above 900 kc, other than to suggest looking for any light dimmers, computers, wall warts, etc. in the vicinity of your radio. Could be interference from one of those types of devices?

--
Ron Ramirez
Ferdinand IN




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Model 80 Transformer resistance
Just forget this number, it is useless anyway. Simply proceed with your project.morzh — 10:08 PM
Philco Model 80 Transformer resistance
My $0.02 is that it is a misprint. I tried to look up the value for the similar 84 and 37-84, and ther is no resistance...MrFixr55 — 09:51 PM
Philco Model 80 Transformer resistance
Thanks for the quick reply! Hmm...well that's good, so what am I seeing that's 1042 ohms on the schematic for the pow...Mike L — 08:46 PM
Philco Model 80 Transformer resistance
The DC resistance of the primary is 8 to 9 Ohm.morzh — 07:54 PM
Philco Model 80 Transformer resistance
I have a feeling the primary winding on the power transformer is bad. My resistance reading on the primary side is 9 ohm...Mike L — 07:48 PM
Rusty Tuning Condenser
I would try Naval Jelly and use a soaked pipe cleaner to get it where it needs to go.RossH — 06:56 PM
38-10T chassis Restoration begins
Hello Dconant , they sold mica to use as a insulator between transistors and their heatsinks too. Rob I will remove th...radiorich — 02:52 PM
38-10T chassis Restoration begins
Thanks for the info guys. I always wondered why the use of mica. Now I know.dconant — 01:52 PM
38-10T chassis Restoration begins
Most common plastics have a dielectric constant in the 3-4 range whereas mica is around 6. This means that even if you w...Steve D — 01:46 PM
38-10T chassis Restoration begins
It is acceptable but not desirable. Plastic is not an approved cap dielectric, and even though a reasonably thick piece...morzh — 11:52 AM

[-]
Who's Online
There are currently 3678 online users. [Complete List]
» 1 Member(s) | 3677 Guest(s)
Avatar

>