[Wilryn]

I have a 51-1733 and would like to do an AM alignment. This is an AM/FM console radio and I have the equipment for AM alignment but do not have an oscilloscope or sweep generator for FM so I was going to do AM only. The FM portion is working and I am concerned that if I align the AM side will that change the FM alignment. Also The cores of the IF transformers are often stuck or very difficult to turn and I am concerned of breaking the core when I try to adjust it. Is it advisable to drop some sewing machine oil in the IF transformer holes top and bottom?
Will this oil or WD40 cause alignment problems in the future. Is there a danger of the cores breaking if nothing is applied in the holes. I have a wood stick which fits in the wide slotted core which appears to be a fired clay material as well as a vtvm and signal generator.
Thank you for any help you can give me.

[Radioroslyn]

Hi and welcome,
Shouldn't have any interaction issues between the 455kc vs 10.7mc alignment. The 455kc coil looks like a series choke @ 10.7mc and the 10.7mc coil looks like a dead short @ 455kc.

Would not use any lubricant on the slugs. It could cause the plastic frame to degrade and the iron power material that the slug is made from. If you break the slug you could replace it w/another from another 455kc transformer.
GL

[Wilryn]

Thank you for your answers
I will do the AM alignment in the coming days.
Both AM and FM are working but the AM is a little weak with stations off position.
I will put some electrical tape over the FM transformers to prevent accidentally disturbing their settings.

[Wilryn]

I noticed an interesting thing when looking at the alignment instructions for this radio.
I have both the Sams and the Philco service manual and the Sams instructions for FM alignment are different and do not make sense. The Sams call for tuning gang fully open
While the Philco says fully closed. Also the connection points are different and adjustment sequence per step is different. For example:

Sams step 1 (o-scope method): 
connect signal generator to pin 1 of 6BA6 through .1 mfd cap
Dial setting at a point of non interference, connect scope to pin 2 of 6BC7
Adjust A10, A11, A12 and disconnect 2 mfd capacitor from pin 2 of 6BC7

Philco step 1 (only o-scope method is suggested):
Connect signal generator to pin 1 of 6AU6 through .1 mfd cap 
Tuning gang fully meshed, adjust TC10 for correct crossover, TC9 for max and equal peaks

The rest of the instructions continue these discrepancies.

I am only doing AM on my radio but thought I would warn others to get the Philco instructions 
If doing an alignment on a 51-1733 or 51-1734. The instructions for 51-1731 and 51-1732 may also be different between Sams and Philco.

The Sams AM instructions say tuning gang fully open, Philco says tuning gang fully meshed.

I thought this may help another member.

[Wilryn]

To clarify my previous post about FM alignment instructions on Sams and Philco manuals
The Philco instructions say connect signal to grid of 2nd IF tube and adjust FM detector secondary then primary (TC10,TC9) with tuning gang closed.

The Sams instructions say connect signal to grid of 1st IF tube and adjust 2nd IF secondary then primary then secondary of 1st IF (A10,A11,A12)
with tuning gang not closed.

That was only the first step for each method, there were more differences in subsequent steps.

AM alignment has tuning gang fully meshed in Philco instructions and tuning gang fully open in Sams insructions.

I hope this clarifies my previous post.

I will be following the Philco manual radio AM alignment.

[RodB]

Hi - Alignment is a lot like what you are comfortable with and what the situation is.  The tuning cap is set to open or closed because there is a good chance that there is no station signal to interfere with your test equipment.  So it's completely up to you.  Injecting the IF at any given point depends on the known status of the IF transformers.  When they are new, they will be set at an unknown position, so sending a frequency of 455KHz through 2 transformers may get zero results.  You get better results if you start with the second IF then progress to the first.  When the radio has been consumerized it is pretty close to being where it should be.  But now some smart guy comes along 70 years later and puts in all new parts which shifts things around a little.  In this case you can get away with the IF freq fed to the grid of the mixer tube, adjust the second IF, then the first, repeat ad nausea.  You will surely see other variations of this routine and it is good to try them and pick the one you want to use.

Rod

[Wilryn]

Thank you for your reply
Makes sense
The Sams instructions also include doing FM alignment using
a signal generator capable of 9.1 Mhz and a vtvm
This radio is a 9.1 Mhz FM IF set. The Philco instructions do not include that option.

[Radioroslyn]

<The Sams AM instructions say tuning gang fully open, Philco says tuning gang fully meshed.

Doesn't matter. If your the rebellious type put it in the middle. The tuning cap has nothing to do with IF stage(s) it's before the IF. What it does do is offer a little bit of resistance to pass the 455kc signal as it's tuned to the incoming signal. It's slightly more resonant at 550 than 1600kc but it's of little consequence. Just needs to pass some 455kc signal thru the rf amp and to the mixer grid and your good. The tuning of the rf and mixer is not absolute in that it does not block all other other signals except for the one that it is tuned to.
GL

[Wilryn]

Thank you, this is very helpful because there is a strong local station at 540 Khz that could interfere.

[Wilryn]

I just completed the IF portion of the AM alignment the best I could. The AM IF cores on the top side bottomed out as the signal was still increasing. The AM band is much stronger than it was but because signal was still increasing on the top side adjustments it probably could be better. The bottom side of both 1st and 2nd IF adjusted correctly. One curious thing I noticed is I also have a 51-1734 and the RC circuit (R15 and C19) coming off the oscillator coil and going to the grid of the 7F8 converter tube is 1k for R15 on 51-1734 and schematic and 1.5k on 51-1733. This would probably affect the oscillator frequency but would it also prevent proper IF alignment? Should I put a 1k in there at R15 where the 1.5k looked original on the 1733.

[Radioroslyn]

So are you using the sam's or philco diagram??  I don't have access to the sam's.
On the Philco diagram c19 is tone compensation for the phono and r15 feeds the hv to the bottom of the 1st if trans.

[Wilryn]

I was using the Sams for R15 and C19. The resistor on the Philco diagram looked like R15 to me so I thought numbering would be the same. I got out a magnifying glass and looked at that resistor number more closely and I think it is R13 on the Philco diagram.
The Philco diagram has that resistor as a 1k. The Sams diagram has that resistor as a 1.5k with a note that it could be 1k on some models.
The capacitor that is in parallel with the 1k resistor on the Philco diagram is a .01 mfd and it is not labeled what number it is. That R/C network is directly above C23 and what looks like C1 and near L3 on the Philco diagram

Thank you

[Radioroslyn]

https://philcoradio.com/library/download...-final.pdf Seems pretty clear to me. NA is awful!!

Don't really care about what the Sam's sez values or placement. It just confuses things. The resistor a cap you mention are in the cathode circuit of the oscillator. They vary the gain of the oscillator tube. They are not a frequency determining components.

I'm thinking they something wrong w/the IF alignment. You shouldn't have to bottom out the slugs. A few things to check. Frequency with a counter @455kc. With the generator set up at 455kc and connect up. Move the dial on the Philco and if the signal disappears you were not on the IF frequency. Always when doing an alignment keep the generator level to a minimum. This means so you can just barely hear it then peak up the adjustment. turn the generator down till you get all of the 455kc transformers peaked up. I usually go over them a couple of times to be sure. Having the generator level up can cause the avc to lower the gain of the tubes in the avc line.

[Wilryn]

The alignment of the 51-1733 has been competed. The tuning slugs are no longer bottomed and all IF transformers have been peaked.
I replaced R17,18,24 and 27 and did the procedure from the beginning with the antenna connected. When I did the alignment earlier this week I had the antenna connected only after completing the IF portion. I verified 455khz with a digital radio and a portable frequency counter. As a further check of 455khz I moved the radio dial and signal did not disappear. Thank you Terry and others who replied with help on this radio. I can now receive WPTF in Raleigh NC which is about 130 air miles away at 3 in the afternoon loud and clear so radio is working good. I did a little peaking of the RF portion of the
FM alignment and that is working stronger also.

[Radioroslyn]

Glad to hear you got it work well![Image: https://philcoradio.com/phorum/images/sm...n_clap.gif]