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

Thread Closed

Philco 38-3 alignment
#1

Completely following the instructions for aligning the Philco 38-3 on the schematic and completely getting nowhere.  Performing the IF align first, then moving to the RF.  The mag tuning switch is closed.  I have a digital frequency counter in line with my signal generator.  I connect the signal gen lead to the cap of the  6A8G, and have tried it with and without the usual lead also attached. Negative for the sig gen is attached to the chassis.  Once I think I've lined up the IF circuit, I can hear the tone continue as I turn the dial to the first position for starting the RF alignment.
The closest I'm able to get is about 60 KC away from where a station should be.  IE, 1080 is coming in at 1020, 650 is coming in at 590, etc.
When the rotary dial is fully closed, it's in line with the tuning gang, so I know it's not off.

I'm getting plenty of clear stations, they are just not in the right place!!!!! Icon_crazy
#2

So, the oscillator seems to be working OK, just at the wrong frequency. You should be able to adjust trimmer 27 to move the oscillator frequency. Try tuning to a station then tweek the trimmer slightly to see if the station moves up or down the dial. With so many trimmers, you could be on the wrong one.
#3

Thanks Rod, I'll give that a try.  I am watching on a multimeter and also listening as I go through the alignment process to get the highest peaks possible.
I just can't turn the volume all the way up - it kills my ears!!!   (and the cat has put out a contract on my life)
#4

Rod, that closed the gap by half, but I'm out of room to adjust 27 any farther...




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
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
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM

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

>