[Tube Radio]

I got the shadow meter coil back today and the rewind job was superb.

Will install it sometime this week and see if that helps the issue I am having.

[morzh]

Congrats. I am yet to see if mine works.

[Tube Radio]

Congrats. I am yet to see if mine works.

Thanks.

[Tube Radio]

I installed the shadow meter and did the alignment again.

The SW alignment seemed to be better, although the SW oscillator trimmer cap seems very touchy.

The dial calibration for the SW band is more accurate now and I no longer have the problem of picking up my RF generator at two points on the dial close to each other. I suppose the shadow meter coil may also act as a filter for the RF preventing it from getting to the rest of the circuitry.

I also checked and the meter action wasn't that good so I re-magnetized the magnet (mine is a small bar instead of the horseshoe magnet) and the meter action is within spec.

Is there any proper way to make there be more shadow movement between being tuned on a station and not tuned on a station?

EDIT:

I got another issue that just cropped up.

At 1500KHz on the dial my RF generator has to be set to 1455KHz in order to receive a signal and the oscillator trimmer cannot adjust it enough. The low BC band oscillator trimmer can get it on 600KHz.

[morzh]

I got another issue that just cropped up.

At 1500KHz on the dial my RF generator has to be set to 1455KHz in order to receive a signal and the oscillator trimmer cannot adjust it enough. The low BC band oscillator trimmer can get it on 600KHz.

It might be the case of "you need to rotate the dial".

[Tube Radio]

I got another issue that just cropped up.

At 1500KHz on the dial my RF generator has to be set to 1455KHz in order to receive a signal and the oscillator trimmer cannot adjust it enough. The low BC band oscillator trimmer can get it on 600KHz.

It might be the case of "you need to rotate the dial".

Maybe so, but in previous alignment attempts and the first alignment attempt since I installed the shadow meter I could get it to align properly at 1500KHz. 

Here's how the dial looks at both ends.

[Image: http://i863.photobucket.com/albums/ab196...161845.jpg]

[Image: http://i863.photobucket.com/albums/ab196...61845a.jpg]



EDIT:

After much finagling of the high and low end BC band adjustments I got it back right again. Is correct everywhere except it is slightly off at 1700KHz.

The oscillator trimmer (rear of tuning cap) has to be set to almost full open though.

I did notice that the shadow meter reads 1.062K versus the 1.1K it should be, but as the meter is in spec far as how large the shadow should be when tuned into a strong station versus no station I'll assume that ohms reading doesn't matter.

On the early shadow meters what voltage is required for a full shadow?

I get these readings

Ohms 788 (resistor and shadow meter coil in parallel)
Voltage tuned to my RF generator at 1MHz 1.923 Vdc 2.4mA
Voltage detuned from my RF generator 6.72 Vdc 8.5mA

Do those numbers look correct?

[Tube Radio]

I have a question concerning my Philco 118 cathedral.

While doing an alignment recently the AM band was in agreement with the dial scale, but all the sudden a few days ago I noticed the dial was a little off at 1000KHz and when the dial is set to 1500KHz to align the trimmers on the tuning cap I now need the oscillator trimmer nut all the way out to get a peak at 1500KHz. Now 1500KHz and 600KHz align perfectly with lower sensitivity at 600KHz. 1200KHz also is correct, but the rest are off by up to 15KHz when they were right before.

Also I removed the oscillator coil yesterday and it looks ok. When I put it back I reinstalled it the same way I took it out including proper lead dress and now I can only get the oscillator to go to 1491KHz when set at 1500KHz with the oscillator trimmer all the way out.

Anyone run into this problem before?

I've tried pretty much everything I can think of to fix the problem and have even enlisted the help of the Antique Radio Forums with no real solution as of yet.

[morzh]

I never align this accurately in the first place. Not that important for me. As long as it is close enough, I am happy.

[Radioroslyn]

As Mike sez. These sets (not just philco) typically are difficult to get dead on and track (having the exact frequency across the whole tuning range). Was just servicing an Emerson 706 from 1952. Cute midget AA5 set. Had a bad 2nd IF transformer (open). Replaced it, all caps, and a burned up 50c5 socket (it fell apart). Aligned the IF and all was fine. The oscillator has one adjustment for the high end of the band (1.6mc). After setting the osc at 1.6mc I tuned in a local station at 1060kc (KYW). Dial is on 1100kc. If I move the osc to put KYW at 1060 now 1600kc is like 1670. So KYW resides at 1100kc.
http://www.radioatticarchives.com/radio.htm?radio=10277

Now if your dial discrepancy keeps you up at nite, you have a lot of time on your hands, and are not easily frustrated look at your tuning condenser. Do the end plates on the rotor have slots cut into them?? If so these can be bent to change the tracking at various points across the tuning range. You can try bending those a bit but you may find that it's just another trade off.

>Also I removed the oscillator coil yesterday and it looks ok
I don't think I've ever had an oscillator coil change inductance all by it self. Typically on Philcos and others it usually works or not. Mica caps are another story but your frequency offset isn't all that much to start ripping in to the micas.

GL
Terry

[Tube Radio]

It bothers me because originally the tracking was pretty much dead on for the AM band. Now the SW band was initially off as I tuned lower, but oddly enough after the problem with the AM band being off happened, the SW band was pretty much dead on before I removed and re-installed the LO coil. Have not checked it after reinstalling the LO coil as I couldn't get a peak at 1500KHz.

The end plates do have slots cut into them. I am reluctant to adjust them as the radio at one point did track correctly with things as they are and as I recall the high end AM band oscillator trimmer did not have to be anywhere near all the way out to achieve that.

I know something has changed, but I have no clue what it could be.

This happened shortly after re-installing the shadow meter. The initial alignment was correct far as I can remember, but then I noticed to receive 1000KHz I had to have the radio set at around 1010KHz which is also when I found the rest of the dial is off other than those frequencies I mentioned which are exactly correct to the dial reading.

I remember one time before re-installing the shadow meter after the initial alignment doing a check using a digital frequency display and very small value capacitor so as not to pull the oscillator which I confirmed by no drop in the AGC voltage at 1500KHz and at each number on the AM band the display showed the correct frequency maybe +/- 2KHz.

[morzh]

Well...first of, it is summer vs winter, the humidity has changed, possibly the temperature too.
This is quite enough to change parameters by measly 1% which would make 15kHz difference it 1.5MHz.

[Tube Radio]

True, although I could understand that being the case if the dial was off by the same amount at all frequencies, but as it is now the amount it is off varies from 0-around 15KHz depending on where the dial is set.

There anyone with a Philco 118 that wouldn't mind verifying at each number on the dial how close the received frequency is to the actual dial reading? That way I have some sort of idea about how the dial tracking should be and will know if I have an actual problem.

[morzh]

I am working on my 118 myself but I am not yet at the alignment stage - I am finishing recapping / replacing resistors which BTW in this radio reeeeeaaaally drifted away, anywhere from 100% to 200%.

[Tube Radio]

Cool. The radio really does sound good once properly operating.

[morzh]

I imagine so. Most Philco large size cathedrals sound very nice. And this one has a pushpull output with transformer phase inverter for it too .