[gary rabbitt]

Hi all,
I rewound the osc coil per Ron's instructions. The set still has the same symptoms.
Basically, it will tune from about 1500kc down to 1000kc, then stop receiving. It is not the tuning cap plates.
The OSC coil rewind did not change any of the previous symptoms.

(I am using the diagram using the 36 tube, although the set is a code (123) EVerything else matches up to it.)

First, here may be a clue. When I remove the grid cap from the #36 tube (Osc) the set will rceive, weakly to the low side of the band.
Upon reattaching the grid cap the set will be silent at the low freqs.

Another thing. When the set is aligned, then I am peaking the set at about 1400, it seems ok, But the n if you make a static or something like click the soldering iron, the set will squeal. Tuning lower will make the squeal sometimes stop, then you can tune back up the band. All seems well, but if there is a loud station or static click, the set will oscillate again.

======================================================
OK, moving to the next coil, I was checking the Ohms on the coupling coil (part 6) between the 35/44 Rf tube, and the 36 tube. The primary shows the correct Ohms, just about 1.6 Ohms.

The secondary shows 0 Ohms, like a shot circuit. It is supposed to be about 9.76 Ohms.

Removed the coil, and seen that someone has probably rewound the outer winding. Scotch tape, and bad soldering.

Now, here are the questions.

Does this look like the right gauge wire for this winding? Sort of looks heavy.

There is a remnant of a thinner wire on one of the rewound terminals. Perhaps this is the correct gauge to use?

Last, as the winding shows zero Ohms , I suspect a thinner wire will show the 9.76 Ohms is is supposed to be.

Guys, can someone either show me a coil, or let me know what the outer winding on this is supposed to be?

Here are the photos, and thanks in advance.
Gary.

[Image: http://antiqueradios.com/gallery/d/91537-1/coil1.JPG]

[Image: http://antiqueradios.com/gallery/d/91539-1/coil2.JPG]
(Here you can see the tap in the primary)
[Image: http://antiqueradios.com/gallery/d/91541-1/coil3.JPG]

[Image: http://antiqueradios.com/gallery/d/91543-1/coil4.JPG]

[exray]

Looks too heavy gauge to me - as in not resulting in enough turns.

The 'light switch/improved reception' thing may be a separate issue. There's a current thread on ARF touching on this.

Ya might be fighting multiple issues there, Gary, I'd address that large wire winding first and move on from there. Its not a critical winding per se but that large gauge wire might be pushing what would otherwise be non-critical parameters.

FWIW - I'm not a noobie at alignment but I swear it took me about a dozen tries to get my 89 to behave. Phases of the moon, how you hold your tongue, etc. It suggested a certain sequence was needed as opposed to a plain "tweak them for max". My radio was a true basket case so my encounter might not apply.

When you hit everything right the 89 is a decent radio.




ht be fig

[gary rabbitt]

HI Bill,

Thanks, Yes, it could be different issues here, so I was going to verify this coil was correct, then move ahead.Using a loupe magnifier, I can see where thinner wire was wound on the temonals wth the thick wire.

As far as the alignment, I have tried just about everything. Slight offtune the IF, and detune the trimmers. At one point, I had it tuning almos the entire band, but then tuning the high end I'd reach about 200 then the squeal would happen. I have followed the alignment to the "T"to get back on track.

I have heard that some have had to hand pick a #36 tube because of issues. I only have 2 tubes to work with but they test on the high side.

Seems odd but If I removed the OSC grid cap, the set would receive (weakly) across the whole band. I tried placing a .01 cap in series with the cap, and it did pick up ok, but there was a very slow oscillation depending on the size of the cap.

I have gone over the circuit again, and everything seems in place, but I think somehow a signal is getting back to the OSC tube and overloading something. I"m not good at working with coils as far as troubleshooting. I have looked at lead dress, moving wires, etc, no change.
The voltages also seem ok when it's receiving. It is pretty sensitive when it does receive.

I know Ron's probably busy, but I am going to keep this coil out until I can find what this winding should consist of.
Well, I'll check back later and I'll see if I can find the ARF thread you are talking about.
Take care,
Gary.

[Ron Ramirez]

Hi Gary

As you know, that winding on your RF coil primary has obviously been redone, and poorly at that with wire that is too thick for the job.

38 gauge wire should be used here as well. I cannot tell you the number of turns - I am away from my notes right now.

This coil should also be baked as I suggested for the oscillator coil.

[gary rabbitt]

Thanks Ron,

I will bake this one also, and whenever you get a chance, let me know the turns on this coil. I know you get busy, so whenever you can, I;d appreciate it.
The OSC coil came out OK, but with no change in the operation.

So for right now, I will concentrate on getting this rewound right, and go from there.

Take care and thanks,
Gary.

[Ron Ramirez]

OK Gary,

The detector or RF coil needs 12 turns of 38 gauge wire on its primary (the outer winding).

Same precautions apply to this as to the oscillator coil (wind clockwise in relation to solder lugs, closely wound, bake coil prior to rewinding, etc.).

Good luck.

[gary rabbitt]

Thank you Ron, you are a lifesaver.

I will get this wound and do the same thing to this coil also, as far as baking it, and rewinding in the proper direction. Hopefully this might solve my issues..

Take care, and thanks again
Gary.