Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Philco 90 grid voltage and RF choke
#1

I am also working on a early pp 45 Philco model 90 and thankfully the filament voltages are all normal.  

My issue is that all the grid voltages are low, some negative.  The set plays very softly and I can tune in stations.  I have completed a re-cap and the resistors and coils all check out.  The plate voltages are ok.  I will be going through the set looking at each grid connection but I was wondering if anyone had a similar issue?

The only thing I found so far is that the RF choke (labeled 52 on schematic) between the 24 and 27 tubes is missing.  I assume the radio played without it so is it necessary and could it drag down all the grid voltages?

Thanks for your help,

David


Dallas Texas


Attached Files
.pdf 90a.pdf Size: 642.5 KB  Downloads: 344


Messages In This Thread
Philco 90 grid voltage and RF choke - by Davidra - 04-10-2016, 02:26 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
hello david, I have a similar generator in my collection that features a cast iron, single-cylinder Briggs & Stratt...radiorich — 01:00 AM
under chassis parts locator diagram for 1938 Zenith 9s262
Has anyone gone to the trouble of creating an under chassis parts locator image?  Yes, I can identify components by foll...bobloney — 08:57 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Try looking at this site the book mark is for a old generator that I was given. David    https://radionerds.com/index.ph...David — 08:36 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Hello Everyone, I am looking for voltage identification for all the pin positions on the socket of a CRV-20130 power su...Tonym4704 — 08:16 PM
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM

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

>