Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

Philco 91 Restore Code ??
#46

Because the usable power rating of it then is (3,200/20,000)*25W= 4W.
Maybe a tad more due to the mass, but not much. You are not using the full resistor.

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.
#47

I wondered about that. Wish there was some place local to get this stuff.
#48

The shadow meter in the radio is responding to tuned signals but it never goes to a very small shadow even on strong signals. Best I can get is about a 3/8 of an inch. Is that about right or should it get narrower? The 1k resistor (#14) has been replaced. Would altering the value of #14 make any difference if so higher or lower?

Also I can't get he lower end of the dial completely lined up. Off about 10kc. The low frequency compensator (#23) is turned out to where it is no longer making a difference. There is a 410pf mica (#24) across the compensator. Could that be a problem and maybe replace it with a different value. The dial is reading higher than the 10kc higher than it should. The high side is spot on.

Thanks,
Dan
#49

410pF is a large capacitance to parallel to a compensator.

As for the shadowmeter....yes, 3/8" is a bit wide, but then it also depends on the station's strength.
Does it go narrower than that when fed a signal from a generator?

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.
#50

The width does not get narrower with generator.

I think I will try some other cap values.
#51

If it does not get narrower with strong signal and your AVC is OK, it could veru well be that the shadowgraph's magnet is a bit weak. Not the end of the world, not even that important: I tune by ear and the shadowgraph is for show and tell mostly.

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.
#52

How do I know if AVC is OK?

For the compensator cap I settled on 330pf. Its much closer now and close enough for me. I tried lower and higher values but lost gain with them. The original cap measured 296pf with my CCC meter. New Fluke 115 is on the way.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
Thank you Arran, this is very interesting information. With your permission, I will definitely use it when I make a vide...RadioSvit — 04:14 AM
The list of my radio & TV collection!
Peter; For a start your DeForest Crosley 6D632 was a 1936-37 model, and I believe it had six tubes, and 3 wave bands,...Arran — 03:07 AM
AES type of Battery Eliminator has hum in B+
This is interesting, they actually designed the B+ side with some form of voltage regulation, I think? Most of the B+ su...Arran — 02:21 AM
AES type of Battery Eliminator has hum in B+
They are trying to use a regulator. Essentially it is an LDO schematic. LDOs are supposed to greatly reduce ripple, so t...morzh — 12:11 AM
AES type of Battery Eliminator has hum in B+
So, I just built a 90 volt 40ma battery eliminator for a farm radio and had to use 1000 mfd for the input filter cap to ...RodB — 10:31 PM
AES type of Battery Eliminator has hum in B+
Caps of 1,000 uF 250V are about $7 in Mouser. C1 could be increased. A NTC inrush limiter could be employed to limit t...morzh — 10:24 PM
AES type of Battery Eliminator has hum in B+
Bruce B — 09:41 PM
AES type of Battery Eliminator has hum in B+
Bruce Could you post the schematic if this power supply?morzh — 09:31 PM
AES type of Battery Eliminator has hum in B+
Hello All, I have built a battery eliminator using the most popular AES K101a. Using plans and all the AES parts  order...Bruce B — 09:27 PM
Need to purchase Old Philco Radio Knobs
Hello Paulo , I have Philco 38-10 too that I am restoring the chassis is almost complete ! Far as my cabinet It is in ...radiorich — 09:00 PM

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

>