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

Philco Jr.
#18

Sound like you've got the sensitivity up too high causing the detector to start oscillating. When it's oscillating it oscillate when it is turn across an am signal. This is what causes that tunable squeal that you are hearing. It's #18 the one with fiber nut on it. Back it out a turn or two and that should calm it down. This does not adjust the IF frequency but control the feedback in the detector circuit.
The fiber nut is easily broken never tighten it down it will crack. If the set is work right it doesn't need to be tight at all.

It is important to do the IF alignment for gain and selectivity. I noted two different fq 450kc & 460kc listed. I would probably pick 460kc that's a much more popular Philco fq, I can't think of any that use 450kc.

Once you get the IF peaked up then adjust the sensitivity just below the point of oscillation.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry


Messages In This Thread
Philco Jr. - by Jim Dutridge - 07-22-2024, 01:56 PM
RE: Philco Jr. - by Jim Dutridge - 07-22-2024, 05:00 PM
RE: Philco Jr. - by Ed Locker - 07-23-2024, 09:16 AM
RE: Philco Jr. - by Jim Dutridge - 07-23-2024, 10:51 AM
RE: Philco Jr. - by Jim Dutridge - 07-23-2024, 11:35 AM
RE: Philco Jr. - by Radioroslyn - 07-23-2024, 04:59 PM
RE: Philco Jr. - by Jim Dutridge - 07-23-2024, 06:33 PM
RE: Philco Jr. - by David - 07-23-2024, 07:35 PM
RE: Philco Jr. - by David - 07-23-2024, 07:40 PM
RE: Philco Jr. - by Radioroslyn - 07-23-2024, 08:44 PM
RE: Philco Jr. - by Jim Dutridge - 07-28-2024, 11:10 AM
RE: Philco Jr. - by Radioroslyn - 07-28-2024, 03:34 PM
RE: Philco Jr. - by Jim Dutridge - 07-29-2024, 07:55 AM
RE: Philco Jr. - by Radioroslyn - 07-29-2024, 03:14 PM
RE: Philco Jr. - by Jim Dutridge - 07-29-2024, 03:38 PM
RE: Philco Jr. - by Jim Dutridge - 07-31-2024, 03:21 PM
RE: Philco Jr. - by David - 07-31-2024, 06:59 PM
RE: Philco Jr. - by Radioroslyn - 07-31-2024, 09:00 PM
RE: Philco Jr. - by Jim Dutridge - 08-02-2024, 03:08 PM
RE: Philco Jr. - by Jim Dutridge - 08-09-2024, 01:53 PM
RE: Philco Jr. - by RodB - 08-09-2024, 07:39 PM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco 91 Speaker Replacement
The spider is glued on the cone and so is the voice coil. I think you can use a cotton swab dipped in acetone and carefu...RodB — 02:42 PM
Restoring Philco 37-604C
Yes I saw that. If I knew, I'd probably try to arrange for getting it myself. But I have just got one. Which does not m...morzh — 01:44 PM
Philco 38-2 Automatic Tuning
When you push the lever, you are supposed to rotate the disk to the desired station. Then the magnetic tuning will acqu...morzh — 01:42 PM
Philco 38-2 Automatic Tuning
I figure out the muting from another picture that helped. Now I need to know how the automatic tuning works. When I push...dconant — 12:11 PM
Philco 91 Speaker Replacement
How would I go about removing the spider from the cone?dconant — 12:04 PM
Philco 38-2 Automatic Tuning
Hello, I am having trouble getting my automatic tuning to stay unmuted. If I play with the tuning handle I can get it to...dconant — 10:51 AM
Does anyone make photofinish replacements?
Here’s the link to the DIY photofinish section of our site: klondike98 — 09:46 AM
Delco car radio Peko vibrator converstion issues
Hi Richard, Thx for posting the schematic.  As I remember as a kid, these were great performers for the time, likely...MrFixr55 — 08:56 AM
Delco car radio Peko vibrator converstion issues
hello mr Fixr, The Electro  Powersupply that I am powering the radio with has a huge choke plus a 10,000ufd electrolyti...radiorich — 10:58 PM
Delco car radio Peko vibrator converstion issues
How about putting a choke in the power supply? The big cap was likely an attempt to stabilize the DC. Kids who cre...MrFixr55 — 09:19 PM

[-]
Who's Online
There are currently 2134 online users. [Complete List]
» 2 Member(s) | 2132 Guest(s)
AvatarAvatar

>