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

Philco 620B Power Up Quirk
#16

Some sets used a shield over the grid lead wire on the 1st audio/detector tube, primarily in sets that used Goat shields, or spray shield tubes, and obviously sets with double ended metal tubes, none of which made it into a Philco. I think maybe some Philco battery sets used a shielded cable on the 1H5 tubes, but I can't remember. Another weak spot, especially with double ended glass tubes, is the grid cap itself, the solder joint can go bad, even if the cap isn't loose.
Regards
Arran
#17

You have to be careful with measuring some 2.5 volt AC tubes on later tube testers, quite often the heater voltage will be too low under load, even more so with #26 tubes on the 1.5 volt setting. The engineers behind some of these testers didn't take the current draw of early AC tubes into account when they were designing the testers, lighting a battery tube that runs on 50 ma is a lot different then an AC tube that draw 1.25 amps at the same voltage. If the tube filament looks dim on something like a 24A or a #47, measure the actual voltage going to the tube socket, you may be surprised.
Regards
Arran




Users browsing this thread: 4 Guest(s)
[-]
Recent Posts
trying to identify this wire type
The red wire is rubber covered wire. The others are cotton braid over rubber often in colors or a tracer, also strand...Chas — 02:43 PM
trying to identify this wire type
Greetings Phorum members, Hope you can help me identify this type of wire in the photo I have attached.  I am not sure ...georgetownjohn — 01:53 PM
Philco 60 Squealing
All correct shields must be in place, all tubes correct no subs of any kind. Check any soldered, riveted ground conne...Chas — 01:24 PM
Philco 60 Squealing
I have recapped and replaced out of tolerance resistors and so on. Radio plays nicely on fairly strong stations. The pro...dconant — 10:55 AM
Philco 46-420 Code 121 Reception issues
Welcome Eric, I agree with Bob and far as the two main electrolytic filter capacitors did you change them yourself or w...radiorich — 11:43 PM
Philco 46-420 Code 121 Reception issues
You mentioned the Philco manual and going through the check points...just to be sure we're on the same page here's the m...klondike98 — 08:13 PM
Philco 42-1008 conversion kit
Interesting. I haven't seen that before.klondike98 — 07:02 PM
12' Philco
Yes I had looked for it on the web as well some time back and could not find it. I was glad to see it turned up in Ron'...klondike98 — 06:59 PM
Shadow Meter Bulb
Now if you had a set with a tuning light then the bulb type is important to the circuit, some sets used those prior to t...Arran — 04:58 PM
Shadow Meter Bulb
Ok. Thanks for the correction.RossH — 03:09 PM

[-]
Who's Online
There are currently 7243 online users. [Complete List]
» 3 Member(s) | 7240 Guest(s)
AvatarAvatarAvatar

>