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Restoring a Model 19 Code 126
#61

Well thanks for the suggestions guys.

Tonite I tried flipping the circuit connections to pins 1 & 2 under to coil. The radio stopped working after that. The only thing I had then is a constant buzzing across the entire band. So I went back to the original connections and assume that those are correct.

I also tried a different 36 tube, but that made no difference.

I am going to do some more experimenting. I may try pulling the coil out and adding a few more turns like Terry suggested.

Thanks,

Mark
#62

Well I have gotten pretty adept at rewinding the tickler coil. I think I have tried about 5 times now. Twice I have gone over 27 turns to 30 or 31 and the radio starts to whistle and whoop all over the band. I think I am going to try 25 turns just for the heck of it.

I am also thinking of making a socket adapt for a 77 tube to see if the radio will oscillate correctly with that, before I make a permanent replacement.

Mark
#63

At this point, I have rewound the tickler 8 times trying to get the oscillator to work across the whole band. But I have just gone backwards. I haven't gotten the oscillator to work as well as it had the first time I rewound the coil (and that wasn't that great).

Ironically, I have a lot of confidence now in coil rewinding, and I think I can accomplish the conversion to the 6A7 tube. I have the instructions from Ron's website and all the supplies.

@Ron Ramirez or anyone with a perspective on this...

Is this is good conversion to make?

If I do it right, do I have a much better chance of success with the oscillator than I have had with the 36 tube?

Mark
#64

Being as how one wrong move can turn your radio into a non-functioning shelf queen,

...you gotta ask yourself a question.

'Do I feel lucky?'

.

.

.

.

.

Well, do ya, punk?


Icon_lol

Seriously, though, you can do it if you follow the instructions on my website to the letter without deviating from them in any way. 31 or 32 gauge magnet wire for the secondary and 38 gauge for the primary. I do not recommend experimenting with wire gauges here, although other sizes might work...but then again they might not. I have only tried this using the wire gauges specified.

Pay careful attention to direction of your windings as well. This is important!

http://www.philcoradio.com/notebook/supercnv.htm

If you do it right...it will tune in stations across the bands upon the first powerup after making the conversion. You will have to align the set, of course.

--
Ron Ramirez
Ferdinand IN
#65

Ok guys, I am going to keep experimenting a little more with the existing 36 tube setup. I appreciate the moral support and advice.

I just had the cabinet professionally refinished. If looks beautiful! If this ends up a shelf queen, it will be one beautiful queen. Icon_lol

Mark
#66

Can't wait to see the cabinet.
#67

Here's the cabinet.  I don't want to even tell you what I paid for this ;-).  Mark

   

   
#68

(04-10-2015, 01:19 PM)markmokris Wrote:  Here's the cabinet.  I don't want to even tell you what I paid for this ;-).

Then don't. Icon_wink

Looks very nice! But, where is the PHILCO decal?

--
Ron Ramirez
Ferdinand IN
#69

Very nice! I love comparing the before and after shots.
#70

Hey Ron,

I have the decals.  They will go on as soon as I can elevate this radio from shelf-queen status Icon_lol .

Oscillating?

Here is where I am at.  I think (I think) the radio is oscillating.  I can pick up three very strong local stations at their appropriate spots on the band, though quite faintly.  I have about 15 feet of antenna wire hooked up.

Also, I use my signal generator connected to the antenna terminal and I can "walk" the signal clear across the band starting at 1400 or so downward.  I inch the signal down, tune it in, inch it down some more.

Right about 830, after a thud, the radio goes quiet, and I assume that is where the oscillator drops out.

But for the life of me, I cannot pick up the oscillator beat in a small transistor radio that I hold right up to the 36 tube.  Could it be that it is not oscillating and I am somehow picking up the signal with no conversion or mixing going on at all?  Do you think it is oscillating?

Antenna Coil

I have been working under the assumption that the antenna coil (2) is good, because I have continuity on the correct pins.  However, when I make the connection in RED below with a jumper (bypassing the antenna coil), the signal gets quite a bit louder.  Still not right, still faint, but stronger.  Does this mean the antenna coil is bad, and I should be rewinding it?

   

I feel like I am making progress, but who knows?


Mark
#71

Measure the resistance from the ANT post to the GND post. If coil is good it will read a few ohms like 10 or less. If bad will read 10K. You know what to do. It"s about the same as the osc coil but not as critical.
Terry
#72

Well I think the antenna coil is good.

I tried to rewind the tickler coil yet again (Going for the Guiness Book of Worlds Records at this point). Each time I rewind it, it either stops working or I get partial operation.

This last time the oscillator started working again pretty well, but promptly cuts out below 850. But it receives pretty well and I can catch the oscillator beat note in a radio I have nearby.

There are many spurious whistles across the band. All I have to do is tap the 36 tube and it can stop working. Maybe some pins in the socket are loose.

I have ordered new 5, 6 and 7 pin sockets. I am going to install a new 5 pin socket. If that doesn't work a lot better I may try the 77 tube conversion, since that is pretty simple.

I may subsequently advance to the full 6A7 conversion.

BTW, can I find replacement coil forms so I don't have to take apart the existing one that almost works??

Mark
#73

Mark,
Have you tried adjusting the cap at item 8? May also be worth reducing the resistor at item 10 to 7500 ohms. Reading through the thread it doesn't sound like these have been tried.
#74

On this latest rewind of the oscillator tickler coil I went to 28 turns instead of 27. I also moved the tickler up about 1/16 of an inch. As is, I only hear a popping sound with the radio on. However, when I attach a 2 ft. piece of wire to pin 4 (the cathode) of the 36 tube, the radio springs to life, sounds great, and I can tuned across the band.

I think this has the effect of a gimmick capacitor. I have tried other small capacitors to replace the wire, but nothing seems to work as well.

I may leave it this way for now with the intention of doing the 6A7 conversion in the near future.

Question about the shadow meter. My shadow meter tests well. If I connect a 9 volt battery, it gives full deflection. But in operation, the voltage across the meter goes from about 9.5V (no station) to 7.3V (station tuned in).

Does that sound right? I get very little deflection.

Any suggestions on that?

Thanks again guys,

Mark
#75

Here she is finished.  It's performing pretty well now across the band.  I know I got carried away with the escutcheon and shined it up too much?  But I like it.  I bought some stuff to age it a little bit, but I may leave it as is.

   

Mark




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