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

Philco Jr.
#16

Received my package from Fedex and all parts have been installed. I brought up the radio slowly and it does work but there is alot of squealing on strong stations but I can get it to tune to a point where the squeals stop and I can understand what is being said. I am missing a shield for the oscillator/detector tube though which I'm sure will help if it was installed so I'll be looking for shield for it.
#17

On my set I find setting the adj for distant stations then going  to a strong (local) it would make noise. That problem has been solved no longer have a local AM station! The nearest station is 90 miles to the East. David
#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
#19

I am going to wait until I can get my missing tube shield installed before I go trying any adjustments.
#20

All OOT resistors have been replaced. All capacitors have been replaced and any documented modifications/enhancements have been installed. Found that I did not need the tube shield that I thought I needed for the detector/oscillator tube. This chassis is the one that was used in the 80 radio with clock. Anyway, I have it playing. Now if I can just muster up the courage to try my hand at cabinet refinishing. I tried posting a short video of it playing but I guess thats not allowed.
#21

You can put the video in a Google folder online then post the link here.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Cannot Adjust an IF Transformer’s cores
Outstanding work indeed. I wish I could come up with solutions like this.slford310 — 11:16 PM
Cannot Adjust an IF Transformer’s cores
The abilities of our 'Phorum Pholks" never ceases to amaze me! Fantastic fabrication, Joseph! I'm waiting now for...GarySP — 08:27 PM
PT-6 antenna connections
Thanks. I never realized that was a notch noted in the schematic as described. I’ll recheck my wiring.bridkarl — 08:13 PM
Cannot Adjust an IF Transformer’s cores
Thank you! I was quite new to the Phorum when I started this post, so I feel like it might be advantageous to publish a ...jrblasde — 08:07 PM
PT-6 antenna connections
Notice in the schematic the notch at the bottom of the antenna coil is between pins 3 & 4. Yes, pin 6 of the 7C6 is...RodB — 07:34 PM
bridkarl
I have two PT-6 chassis. On both there is a blue wire that runs from the above chassis transformer to pin 6 of 7C6. So t...bridkarl — 07:23 PM
Cannot Adjust an IF Transformer’s cores
Joseph, now you are an engineer!!RodB — 06:37 PM
PT-6 antenna connections
Hi, reading your explanation I can see the confusion. If you take it one connection at a time it should result in a desi...RodB — 06:34 PM
Cannot Adjust an IF Transformer’s cores
It works! I received the PCBs this morning in the mail, and put everything together. I reused the base from the original...jrblasde — 04:32 PM
PT-6 antenna connections
I seem to have lost my way on this PT-6. I see the antenna aerial transformer schematic - I’m reading pins 1 through ...bridkarl — 12:30 PM

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

>