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42-1008P ALigntment - Printable Version

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42-1008P ALigntment - Edisla - 05-10-2015

I have the BC band aligned as good as I can get it. A tad off on the higher freq's but not to bad.

As far as the SW band goes it is a bit off.

I followed the instructions and get 15MHz dialed in but then when I go down to 10MHz to dial in WWV it actual sits around 10.2-10.3MHz

Is this normal?

Do these things never line up as good as we'd like?

RE: 42-1008P ALigntment - Warren - 05-11-2015

You Know. Aligning a radio is more than just getting the stations lined up with the dial. Afteran 'alignment" the stations should come in clearer, etc not just on the dial mark.

RE: 42-1008P ALigntment - vecher - 05-11-2015

I just had same thing happen on my 42-1012 see thread. Found that the Mica Caps around the Osc tube were way off in value. After replacement radio worked and aligned perfect. Also if you get same stations on 2 different frequencies about 1 Mhz apart (image) replacing the mica caps take care of that too.

Skip...

RE: 42-1008P ALigntment - Edisla - 05-11-2015

I guess I'd better go find your thread and look it over.

I am getting that same behavior.

RE: 42-1008P ALigntment - vecher - 05-11-2015

I had the Caps on hand. Normally you do not have to replace Mica Caps. But looks like these old radios some if not all of the caps drift. Do you have a capacitor meter? easier to check caps around your Osc tube then trying to replace all of them.. Mine were way out of spec..

Skip...

RE: 42-1008P ALigntment - Edisla - 05-11-2015

Looks like she'll be heading back to the bench Icon_smile

RE: 42-1008P ALigntment - Edisla - 05-11-2015

Looking into the mica's now and they don't seem to match up w/ my schematic.

Example: (13) says it's supposed to be a 325 but I read it as a 23 (red, orange, blk???), (4) supposed to be 250 I read it as 600 (blue, blk, bwn)

I also see a resistor (12) on the schematic that is not there. Well its not where it shows in the drawing.

Getting confused :\

http://www.nostalgiaair.org/PagesByModel/487/M0013487.pdf

ETA: I need to double check things. I must be looking at things wrong.

RE: 42-1008P ALigntment - vecher - 05-11-2015

You need to measure the Caps using the Capacitor tester. The mica Caps read a little different depending on if they use 3 dots or 6 dots. Plus it hard to tell the colors on them since they are over 70 years old.

SKip..

RE: 42-1008P ALigntment - Edisla - 05-11-2015

Ok here is what I see comparing schem to actual parts


Schem / actual part

(4) 250uuF / 600uuF (BL,BK,BN)

(5) 360uuF / 046uuF (BK,Y, BL)

(10) 10uuF / 10uuf (BN, BK, BK)

(12) 680ohm / 1k and found it tucked behind and right on the Osc. coil terminals

(13) 325uuF / 32uuF (BK, O, R)

(16) 300uuF / 300uuF (O, BK, BN)

(20) 250uuF \ 600uuF (BL,BK,BN)

(24) 250uuF / 250uuF (R, BK, BN)

From what it looks like these appear to be original from what it looks like anyway. (5) and (13) I'm not 100% on, hard to get to and values of what I am getting from the color codes seem odd???

RE: 42-1008P ALigntment - Edisla - 05-12-2015

From what I can tell the two important ones to focus on for SW alignment are (5) and (13).

My meter is reading 360 for (5) and 370 for (13)

RE: 42-1008P ALigntment - Nick3092 - 05-12-2015

Most of the Philcos I have worked on seemed to have some nonstandard color code on the mica caps. Other manufacturers micas seem to use the standard code. But it seems like Philco had some other color code on them.

RE: 42-1008P ALigntment - vecher - 05-18-2015

Have you made any progress? Another way to bring in the alignment is to put a small value cap across the tuning cap to give it more range.. That will not take care of the signals appearing on frequencies approx 1 Mhz apart, it will just allow you to get the frequency and dial aligned.

Skip...

RE: 42-1008P ALigntment - Edisla - 05-20-2015

Following the instructions the best I can get is 10.2MHz on the dial for 10MHz and 15MHz on the dial for 15Mhz.

RE: 42-1008P ALigntment - Ron Ramirez - 05-20-2015

That is pretty good, actually. You may not get any better than that.

RE: 42-1008P ALigntment - Edisla - 05-20-2015

Well if that is expected then I'm going to call it.