The PHILCO Phorum

I just bought this for about the cheapest I've ever seen a cathedral sell for down here in Kiwiland... so I'm pretty stoked.  Just asked them to pull the speaker and post that separately... hopefully they're ok to do that.  It will be in the loving care of NZ Post for a few days... and they are every bit as careful as what I believe the USPS to be...
[attachment=9888]
[attachment=9889]

So what do people normally do with these?  Display only?  That probably won't cut the... erm... mustard...  for me.  I'd like to restore it the same way I have done my 89B I posted on here a while back.  Are the holes on the front panel the same as the 19 or 89 does anyone know?  Potentially I will put the restored 89B chassis in this cabinet until I work out what I'm doing with the 89's original (badly damaged) cabinet.

How should I power it?  2V for the filaments doesn't seem like the easiest voltage to come by... how critical is it?  I could easily build a power supply to provide the lower voltages but 67.5 and 135V could be slightly trickier.  Can you series-string 2 or 3 tubes to get to a more manageable voltage?  Just throwing ideas around at this point...

Whats cool is it has a history... the current owner remembers listening to it at their grandparents farm in the 40's... I've asked them for more of that story... radios with stories are 346% more awesomer 

Anyway, I was quite pleased with the purchase... just wanted to share it.  I know you're all wishing at least one radio in your collection was mustard coloured too   

Cheers

Steve

Steve

The very first complete radio I ever owned, an RCA Victor 5T1 tombstone I had about 100 years ago (okay, 42 years ago) was painted a similar color. To this day I am still impressed at how sensitive that radio was once I restored it...I put up a 100 foot longwire that was only maybe six to seven feet high, and with it I could listen to WLS in Chicago in the daytime from my house in western Kentucky, a distance of over 300 miles. Back in the 1970s, rock music was still being played on AM (MW) radio and WLS was one of the biggest radio stations in the country. But I digress...

That is a neat find in spite of the paint job! The original grille cloth looks good; take care of it, that pattern has never been reproduced.

You can build a power supply for it to furnish the proper voltages. I built quite a few several years ago. Since your country probably uses 220-240 volt AC mains it may make this a bit more difficult, but it can still be done with a suitable transformer, a handful of Zener diodes, a few resistors and capacitors, and a voltage regulator for the filament voltage.

Thanks Ron, and now I'm paranoid about that grill cloth! Hopefully it survives. Hes going to remove the speaker (is that a plug on the back or just some unusual strain relief block where the speaker wires enter the chassis?) and ship that separate from the cabinet. The cabinet will be wrapped in carpet underlay and boxed.

Power supply it is.. an LM317 should deliver the required filament current which I calculate as around 680mA all up - does that sound right? Seems a little low but the 30 and 32 tubes only have a 60mA filament current.

Cheers

Steve

 Hi Steve. Nice find. That is a speaker plug should unplug from chassis fairly easily.

  

Nice find Steve! Post pics as your restore it, we'll be watching.

I am surprised the speaker has a plug, this type, they often have it soldered, like 60/66 series. Plug makes it oh so convenient to fix.

Yep the speaker plug is handy... I know my 89B and even my 37-6XX radios don't have them... Having said that I will rewire the speaker with new wire anyway...

I'm looking forward to seeing what condition its in underneath... (the chassis AND the paint)...

Now that I think about it, I believe that every model 38 I have ever seen had the speaker plug, while the model 60 (AC mains version) has the speaker wires hard-wired (no plug or jack). Strange, huh?

Could it be that the early big heavy PM speakers these radios had needed maintenance (do they lose their magnetism over time?) or were thought to be unreliable, so their replacement was facilitated by a plug?

(04-17-2016, 04:30 PM)Ron Ramirez Wrote: [ -> ]Now that I think about it, I believe that every model 38 I have ever seen had the speaker plug, while the model 60 (AC mains version) has the speaker wires hard-wired (no plug or jack). Strange, huh?

PM? I thought that time they all came with FC speakers.

So did I until a few weeks ago.  I have another NZ made battery set (1934/35 vintage) that I posted about recently which also has a PM speaker:

[attachment=9895]

And if you have a look at the pic in the first post here, you can see the huge magnet in the 38a.  I guess it was to reduce the power requirements & conserve battery life.

As Model 38 was a battery-operated receiver, it used a PM speaker as did all of Philco's battery-operated radios of the time.

Now, you found electrodynamic (field coil type) speakers in AC radios as well as many car radios of the period.

That kinda reasonable: field coil draws lots of power and with batteries one tries to save every morsel of it.

 I don't think that it will be too difficult at all to construct a power supply for this radio. For the "A" side a 6.3 volt transformer, with a center tapped secondary should do the job, just wire up the 6.3 volt winding as a full wave rectifier with a grounded center tap, then you will have 3.15 volts to filter and drop down to 2 volt DC at the proper current level, a combination of a silicon diode and a resistor shunted across the output should do, without a voltage regulator you will need a proper filter choke, a resistor won't cut it. For the "B" voltages, a transformer with a 150-200 secondary should do, with a bridge rectifier, then a Pi filter arrangement, either RC or LC, followed by a voltage divider to get the two or more B+ voltages you need. Probably the easiest way to construct a power supply for battery radios is to use a power transformer from a scrapped AC tube radio, preferably from a small set like a five tuber, the only drawback is that the high voltage winding is often a little too high, like 180 volts on up, which you will have to reduce.
Regards
Arran

Thanks Arran, I should be able to knock something up... the cabinet might be a more difficult proposition... I'm starting to understand the paint job now...



Damaged, doweled and glued, filled, and then painted. There is another spot similar near the top on the other side... something was dropped on it, or it was dropped on its head. This break is right at the end of the top brace...

Sigh... woodwork... not my forté. I'll start a cabinet restoration thread because I will need all the help I can get with this one...