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Model 16X - Problem With Radio Reception
#16

"I guess the moral of this story is where possible never change more than one cap at a time, and keep checking the radion reception after each change."

You have that right Icon_smile It's amost always possible to use the change/test method. The only way it would not be practical is if the caps were in a module that you had to disassemble or unwire a section to get to the caps ( 3 or 4 behind Philco pushbutton mechanisms.)

We have all seen guys take a working radio then 'shotgun' all the caps (sometimes resistors too) then have a non-working set. Now, where do we start looking for the trouble? The whole set, that's where. You'd have to trace every connection made, and verify it was all correct according to the schematic. In effect they have created more work than necessary. Lesson learned.

Change the filters first, test. Then one or two caps at a time, test again. As you can see, troubleshooting is easier when you know what cap you just installed. Miswire, or wrong value you know where to look.

Just a quick thought about not receiving below 700. Hope this is the issue. Check for shorting tuning cap plates. You may see one or more plates bent creating a short when you hit 700 on the dial. Static, then no reception sounds like that's what happening. Turn the radio on, bring the tuning just to where the set stops receiving. Tune back and forth a bit. I'll bet it's static just before it stops. Leave the tuning cap in that position
Next, get in there with a good light and magnifier, then look straight down through the plates and see if you can see two touching. It might be touching ever so gently, but it will short out.
If you find a spot that you suspect, you can take a cut piece from a business card , slip it into the gap and see if the reception comes back. Once you find the spot, you can tune out the plates, and make a TINY correction to the plate.

I have seen some plates that have tiny 'hairs' from the aluminum on them and sometimes that shorts out. In that case, running a strip of business card down each will help clear them. But try the other test first.

If you do have shorting plates and still can't find them, there are other ways to deal with it, we will talk about later.

Hope this is all it is, let us know.
#17

Thanks again Ron...I'll check the plates! Sonny
#18

Hi Gary. Thanks very much for your thoughtful and detailed response. I will check the plates as you suggest today and see if that takes care of my problem!

I'll let you know how it goes Icon_angel ! Sonny
#19

Hi again Ron and Gary. Well, once again you guys were right on. I checked the tuning plates and sure enough there were 3 that appeared to be very slightly bent one way or the other. I very slightly adjusted all 3 and wallah Icon_surprised , instant reception on all bands on all frequencies Icon_biggrin ! The radio reception is now good on all 5 bands left to right and it sounds great!

I wish I could say that this one has been a lot of fun...it has, but it has also been frustrating at times. But it was a real learning experience and I now already have my next project, a Philco model 51 recapped and it has great reception and sounds great as well!

Well, thanks again for your help. I'm sure I will be back soon for more guidance on a new project. Sonny 8)
#20

Sonnyboy Wrote:I wish I could say that this one has been a lot of fun...it has, but it has also been frustrating at times. )
Hi Sonny,
Glad that it was only the plates. Now that "frustration" turned into something you will remember the next time those symptoms come up. I know what you mean though, I get problems that come up and I am at a loss as to how to fix them. We all do, When I reach that point I may put the radio aside and take a break, or work on something else. Come back later and find the problem easily.
We get so deep into a situation sometimes we fail to remember the basics.. Part of the fun Icon_smile

One thing on bent plates though. There are some plates on the tuning cap that have slits in them. Those plates are meant to be bent so that the tracking of stations remains correct. The bending slightly adjusts the capacitance at a certain point to keep the stations correct on the dial.
The other plates should be straight.
Good luck on your next sets.
Gary.




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