[Marsupial]

Greetings Philco gents and ladies. 

Years ago I began work on my very own 47-1230 and got it to a point where most of stages 1 and 2 of the schematics are essentially recapped, fuses and ground has been installed, essentials changed to get the radio safer, and cabinet refinished, as the finish was Sun damaged and veneer was missing.

Here's an old thread about it. 

https://philcoradio.com/phorum/showthread.php?tid=3110

At that time I also shipped (gifted) the D-10A changer to another 1230 owner.

Sadly life happened and the radio remained untouched and un powered for years as my life changed. 


Last year I got a likely "aftermarket update" in the form of a Voice of Music changer from 53, that has 45s & 33s (and 16s but who cares?)

Soooo, 1230 now sees lot more air time, and I realize I never finished with its restauration... While AM is good, nothing plays on AM here. 
FM and Phono are low. And a bit gritty. 

They share the same tubes. In stage 3.

I think it's time I attack this part of restauration, at last. 

Soooo.... Here's what the guts currently looks like. 

I have a resistor I want to change, some safety caps that are waiting to be installed, and several caps to continue my quest.

[morzh]

Well, it's.....colourful

[Marsupial]

Yeah, more than paper caps for sure.

I go with the philosophy that I want the next tech inside to know what's been done and what's original. So the caps have schematics numbers directly on them.

I find it helpful

[Marsupial]

This evening I was trying to fix the limit switch that turns the phono light on.

After much contact cleaner, opening the switch and cleaning, I came to the conclusion that it was just too damaged and that's what was causing it to not fully retract to off position when in use. So I added a return spring (green arrow)

Then, upon reinstalling, the hole for the pull spring teared out. (circled orange)


... I don't really want to pierce another hole. The whole design was strange at best. 
I guess I'll just install a modern switch like I was trying to avoid.

[morzh]

Put a metal eyelet in.
Ot a screw with an eye cap, with two good washers and a nut to clamp against whatever material it is (mdf?)

[Marsupial]

It feels like it is some sort of cardboard. Or aspenite? 
It's from 1947 what did they used back then that looked like thick solid cardboard?

I'll def try to find some sort of eyelet that work. 

It is the mobile part, moving away from the switch.

I'll think about how to fix it... It's never been working since I own that radio.

[Marsupial]

So for my first step, I've followed some helpful hints.

I've changed c100 and c101 (installed safety caps). This was suggested long ago by Ron Ramirez, thanks a lot.

And @criageek hinted that r100 was problematic, I've had a similar value to his... It's replaced now and I'm certain my FM and Phono are less gritty and more loud than before the change. Plus, I had a bad soldering spot, so it was twice worth it.


Phono still not as loud as AM, and hummy. Hoping the current recap of section 3 will help with that.

[Marsupial]

This evening I change several caps. Focusing on stage 3, I changed all the caps in the mf range that haven't been done before. 

 I haven't changed c307 yet. Because of location. I don't want to dismoubt the sub assembly to get to it.

Anyone know of a trick?

It is between the chassis and the switch assembly...

[Marsupial]

The radio is clearer but FM and Phono are still lower volume than AM.

As a result, I need to crank the volume up.

At that high volume, noise is also amplified (slight hum?)
This can be filtered out by turning the tone knob clockwise, but it sounds less good and reduce volume on some of the frequency range, soooo...

AM is crystal clear and loud. But besides traffic report there's not much.

So, there's still something to change if I am to get the same quality out of my Phono & FM than my AM.

Any ideas where to look at?

[Marsupial]

I'm trying to find a way to remove the paper/wax C307 from the circuit. Problem is, it's the farthest-most component behind the band switch.

Without disassembling the whole thing, I can't seem to find a way.

I mean, I could even leave it there if I manage to cut it off, and I could use an alternate ground location for the replacement.

But I can't seem to have big enough access to it to allow for cutting it out.

Anyone has tricks on how to do that?

It's connected to pin 6 of the 6BA6 and serve as screen rf bypass... What wrong would it do to not recap?

[RodB]

If you have physical access to some of the cap see if you can spin it off the wires. Leaky screen bypass caps cause a lot of trouble. Generally, hot screen resistors.

[Marsupial]

Thanks RodB.

I barely can touch it with a screwdriver. It's well hidden behind the bandswitch and a bunch of other parts.

I was looking at just clipping the connections on both ends, but I don't have thin enough cutters to even get to either sides.

Right now, it remains inside the circuit, unchanged.

[RodB]

You can try removing the nut holding the band switch, move it left or right to get better access. I was going to suggest poking or pushing it off the wire but if that is unsuccessful then you would create a new problem.

[Marsupial]

From what I've seen, the bandswitch is held on the knob side by the mechanism connecting it to the knob, and on the other side by a bracket that is bolted to the top of the chassis.

I tried removing this bolt, but the whole switch assembly didn't move much. Not enough for me to access the cap. 

I don't know that I want to dismount the mechanism between the shafts and the knob. Anyone ever tried?

[RodB]

I don't have any other ideas. It's worth pursuing because it's an 80 year old paper wax cap. Maybe keep it in mind for now and when something comes up attack it.