The PHILCO Phorum

(07-05-2015, 11:38 AM)TA Forbes Wrote: [ -> ]Frustrating when a relatively simple set kicks ones ______

You can say that again...and thanks for the support, very much appreciated...

Well, I began to reassemble the set.

By mid-afternoon, it looked like this:



And now, it looks like this:







Of course, now I find that I need to order a few parts so I may finish this set up. Therefore I shall do that, probably tomorrow evening. It needs a new dial scale anyway, so I'll probably just order everything from Radio Daze.

I just made an order from them myself. A 630 dial and some other odds and ends. 

Which reminds me- a Psychiatrist and a Proctologist have joined here to form a practice together. 

They have named their practice "Odds and Ends." 

Heh heh heh........

Well you don't give up easily. Who knew when you started this restore it would turn into a major restore of the chassis.
Thanks for continuing to post what you are doing as you go.

ron
well you just gona leave us hanging here

Patience, Sam...

The parts I ordered from Radio Daze finally arrived early this week. I have those, plus a different speaker to install in this set. Perhaps tonight I'll get going on it again.

I'm wondering how well the new wiring that is close to the dropping resistor (62) will hold up. That resistor gets really hot! I'm wondering if perhaps I should have installed cloth-covered wiring in that area.

Well, I did do some work on it tonight. I knew I had better get busy on it before Sam fires me!

I still need to install and hook up the speaker, install two more capacitors, and reconnect the wires from the set's front end, and it will be ready to try out again. So, either tomorrow night or this weekend, I'll have it ready to try out.

Success...sort of.



Yup, my SSTRAN now comes in nice and loud (and on the original speaker, yet!). But the quality of the audio...I don't expect high fidelity out of this little set, but the audio quality is sorely lacking. Perhaps the voice coil is rubbing. I also found that the 1st IF breaks into oscillation if the adjustment screws are tweaked too much. And it goes into oscillation on the SW band.

Could be (at least partly) lead dress issues. Since this set no longer follows the original schematic, I did change some of the wire routing in an effort to make leads shorter and more logical.

The circuit mods eliminated two bakelite blocks and a few resistors.

A big concern I now have is: How in the heck do I align this (AC/DC) set without tripping the GFCI that protects this circuit? I can't attach my signal gen to this radio without tripping the GFCI.

well about time. thought I was gona have to get kirk to help you

Hey Ron.  Just grasping at straws here, but have you tried running the signal generator and/or the radio through an isolation transformer?  May do nothing at all, but could it possibly filter the noise upsetting your GFCI?  Nothing to lose trying. Take care, Gary

Ten days later...nothing new?   I know you didn't give up on this radio!  Take care, Gary

Actually, I have sort of given up. For now, anyway. I'll eventually return to it.

I tried running the 604 through an isolation transformer. As soon as I clipped the negative lead of the signal gen to the chassis, SNAP went the GFCI and OFF went the power to that circuit.

The only extended time I now have for radio tinkering is on weekends, and I've been doing other things lately instead.

Greetings Ron, Hope the New Year is treating you well so far. I was thrilled to find a detailed thread on the 604C. I am working on the one I acquired at my 1st Radio Swap Meet in October. I too am having issues. I can get a faint, distorted signal from the strongest local station, and my SSTRAN. Trying to align it, I had the same problem hooking up my Signal Gen- it would pop the GFCI. I appreciate all the detail pics and step-by-step. I was looking forward to seeing the final post of this running. My heart dropped when I saw it is "...to be continued." I may start a thread documenting my progress. I'll subscribe to this one, in hopes you get back to it soon. Cheers, Jeff W.

Five years on...I finally fixed it.

https://ronsradios.com/2020/09/19/philco-model-604c/

Wow Ron,.....that's one long undertaking

Couple of these popped up on eBay within the last 3 weeks. Litetally raining them 604Cs.
I had to hold myself by the hair of my ...chinny-chin-chin.

If I had only dug deeper five years ago, and re-tested those tubes at that time, I believe it would have been fixed in July 2015.

And Mike, thanks for your recommendation of the Hammond choke. Between that and the higher value input electrolytic, it is hum-free.