[morzh]

https://philcoradio.com/library/download...l.%202.pdf

The alignment procedure is here, at the end.

[georgetownjohn]

Thanks for the reply MORZH. I was really headed in the wrong direction before your reply. I have started to get setup using the correct instruction thanks to you, John

[morzh]

Sure.

I would encourage you (and everyone) to briefly glance through the original Philco docs (which we have here in our library) or Riders (they have the same, the on-line scanned copies are on Nostalgiaair.org website for most of the radios).
This might answer many (even if not all) questions before they are asked.

[georgetownjohn]

Ok, now I have run into a problem in trying to do the IF alighnment.  The meter I have to use is a Triplett 630PL.  I am following directions in the 37-640 and it says to set the meter to 0 to 30 volt range.  I assume that should be AC volts?  I do not have a 30 volt range and I including an attached photo of my meter if that helps.  Here is the first problem I am running into. I have connected up the meter to pins 3 and 8 on one of the 6F6G tubes as it says and when I turn on the radio, the meter pegs out to max when connected to the meter ac volts and common connection. But when I put the red meter lead in the output connection of the meter, it seems ok by not pegging to the max of the meter.  However, I do not get any results in adjusting 34S/34P, 33S or 33P.   During this time I had the sig gen connected up to the grid cap of the 6A8 tube with a .1 cap per the instructions.  I did however, have the grid cap connection from the tuner removed from the 6A8 while doing this.  
Now, if I connect the sig gen to the grid of the 6K7 IF tube, I hear my sig gen tone loud and clear and can adjust levels on 34s and 34P for the highest level. I do not get any results however when adjusting 33S and 33P. 
I wish I was smarter and could explain the problem better. I know I must be doing something incoreectly and I hope someone can help me make sense of this. Thanks, john

[morzh]

Yes, the meter should use AC setting. If you do not have 0-30V, then you use 0-50V. It should not peg out, but can possibly have initial throw.
If it does, start from a larger scale like your 250VAC, and once the transition passes, go back to 50VAC.
The scale itself is not important, it is just, as always, you want to use the lowest possible one to have better resolution / track minute pointer movements.

You also should show the settings you use on your photos, else we only see it on "Off".
Also, could you please refer to the pins by function and not just the number. Else you send people to figure out "what are the pins 3 and 8". I know they are K and A., but still.

I am not sure what you are doing with this meter. If the meter is OK, (and the convention is Black is Common).
Your Black lead should be in your COM- jack.
Your red lead should be in your OUTPUT jack.

Your range should be set to appropriate AC Volts and your Polarity switch should be at the top (DC+, Ohms and ACV) position or else the polarity will reverse.

This is it. If it still pegs out, and stays pegged out, your DC blocking cap could be shorted.


And. If you connect to the 6K7 grid cap but remove 6A8 grid cap...guess what happens? (a hint: no, your meter won't react).


PS. Personally, I always prefer the meter on AC volts across the output of the power xfmr (or the speaker which is the same). Today's DMMs are fairly accurate and you will see the change.

[georgetownjohn]

MORZH, Thanks for the help as always. Yes I have more to learn as you point out. I have the meter switch set to DC+/AC volts. But guess what ahppens when I remove the grid cap from the 6A8G, no change --470KC tone is loud and clear and adjustments still work on 34S and 34P. I beleive that ths may be because of the change Philco made on IF transformers on my run as described in Service Bulletin 250 for code 121- 37-620 and in Service Bulletin 253 for code 121-37-640. Fortunately, the spare parts chassis 37-620 I have is also this later run as is my 37-640. Concerning getting no results when adjusting 33S and 33P, I think that IF transformer is open. It is the one I had earlier opened becasue I could not get a good ohm reading. Soo I will take that IF transformer from my 37-620 chassis and install it in the 37-740.
Wish me luck, John

[morzh]

Before you do anything. Why change a perfectly good IF transformer?

I thought you put the sig gen to the 1st RF 6K7.
So far everything is good.

Your signal should be put to the cap of 6A8, and both the 33 and 34 IF xfmrs should be able to be adjusted.
Once you peak them out, proceed to the next step.

[georgetownjohn]

What is confusing to me is why do I not hear the sig gen tone when connected to the 6A8 but I hear it loud and clear when connected to the 6k7. Also even when I watch the meter if I connect to the 6A8, I still not get a meter reponse while adjusting 33S and 33P which tells me that IF ransformer is not working.

[morzh]

OK, the sch says there should be 7/11 ohms across Prim/Sec widings of the 1st IF xfmr. Is this the case?

[georgetownjohn]

I get 21 ohms and 11 ohms.  That 21 seems to be too high.

[georgetownjohn]

I just also checked the IF transformer from the old 37-620 chassis I have and I got 8 ohms and 15 ohms which seem more realistic.

[georgetownjohn]

Does anyone know where I can find a part number 42-1184 which is AC power and tone control for a 37-660.  Apparently it is different from the spare 42-1182 that I have.

[radiorich]

Hello Georgetownjohn,
Here is a great source for controls  Mark Oppat

https://oldradioparts.net/

Sincerely Richard

[RodB]

Yes, the 1182 is a 4 position tone switch, as in the 37-630, and the 1184 is 5.

[RodB]

Richard, these are 2 rotary switches on the same shaft, not pots.