[Arran]

Hi;
I picked up a radio today, that I wasn't expecting to find, nor was I looking for, at a garage sale. It's a Model 706A, a Canadian edition of one of the Bing Crosby 1201 models. It looks like it's all there except for the speaker, I already have one that I salvaged from a pair of junker 1201s that I parted out years ago. The cabinet needs refinishing, so I will be able to see if I can come up with a replacement for the Philcocote faux teak wood grain, but it is physically sound and solid.
I did run into an interesting problem, one that I should have noticed before buying it, the power line frequency isn't 50-60 cycle, it's 25-30 cycle. This isn't a problem for the radio, it's an AC/DC power supply, but I won't be able to operate the phonograph as is. So I am contemplating how to deal with this, it would be easy to swap motors, if I still had one from the units I parted out, I could see if I have another that's close, or I could find another method. Has anyone built an inverter to convert 60 cycle AC to 25 cycle AC? Could the motor be modified to operate from 60 cycle, by removing several turns of wire for example? This is assuming that the phonograph hasn't already been converted for 60 cycle use.
Best Regards
Arran

[Texasrocker]

Hello Aaron. Since your turntable motor wont do on 25-30 cycles, anything would be worth a try I suppose? Ive tossed more orig Philco phonos than Id ever like to admit also. If I still had one, I could spare you a good 60 cycle motor indeed!Ive run across several Canadian made Philcos myself, and even the Canadian 25-40 cycle all AC sets transformers ran much "hotter" than usual, after extended time on 60 cycles. Its not supposed to "matter", but I noticed it several times in the past. It took those vintage 25-40 cycle AC trans awhile to heatup, but lordy-mercy,they got there indeed! I swapped em out for 60 cycle trans that I had in backstock from other old sets. Bet you can find a 60 hz motor for it!! I still see lots of Philco consoles in junk-shops these days with orig 60 cycle type turntables still attached.There out there!!

[Arran]

I have an update, when I had a few moments the other day I removed the Masonite cover from the bottom of the phonograph and had a look at the motor. The first thing that I spotted was a pair of bright blue crimp connectors in series with the motor power leads, so the first though was that someone had been in there before. So I thought that I would shine a light in there to see if the colour of the wires matched on either side of the connectors, they did not, at the same time I spotted some writing on the motor, it read 120 Volts, 60 Yccles, they misspelled cycles. When it was replaced I can't say for certain, but it looks period, with cloth wires, and it may even been from the same supplier as the original. The Ontario had an appliance rebuilding program in the late 1950s to accept the power frequency change from 25 to 60 cycle, which is where this beast came from, especially for appliances with motors. This situation was a good example of why it is worth keeping at least a few old phonograph and clock radio motors around, you never know when you might run across a burned out unit or a 25 cycle one.
Best Regards
Arran

[Texasrocker]

Thats Great news Aaron! Thanks for the update. Just bet you will have your set working like new in notime at all.

[Arran]

After some investigation I found out the the original 25 cycle phono motor, it's mounting plate, and idler wheel was manufactured by the Alliance Tool and Motor Company. After looking at the 60 cycle replacement motor I found out that it was also made by the Alliance Tool and Motor company, so in other words it's an O.E.M replacement motor, a lucky break there. I will need to study the electrical/mechanical aspect of this mechanism, the operation of the mercury switch to be specific, something doesn't look right about part of it.
I conducted a little research on the circuit used in the radio itself, the model number is a 706-A, on the paper tube diagram inside it says model 706 but it has a factory correction for the rectifier tube from a 50Y6 to a 50X6, which is what the chassis has. There seems to be several different versions of the 1201 series, the 46-1201 code 122 uses a 50Y6 and a 50A5 with the 50Y6 wired as a half wave rectifier, the 48-1201 on N.A uses a 50X6 and a 50A5 with mini IF cans, my 706-A uses a 50X6 and a 50L6, both my set and the 48-1201 have the 50X6 rigged up as a voltage doubler. So in other words the audio output stage will be capable of a little more kick with 180+ volts on the plate and 125 volts on the screen grid, in effect it's a transformerless power supply circuit and not an AC/DC one.
I will tell you this much, as much as I admire much of Philco's engineering I don't like certain aspects of this unit, in fact some are stupid, aside from the Philcote faux finish on the cabinet. While they cleverly designed this unit so that the top flips open to access the tubes and the phonograph, in order to remover the chassis from the cabinet you have to unsolder the phono input lead, the two power wires going to the phono chassis, a ground wire tying the two chassis together, and the two leads of the loop antenna. Would it honestly have hurt them to use sockets, plugs, or even spade connectors to connect the two chassis together? I know that Philco hated all things RCA but a RCA jack and socket would have been the smart way to connect the phono input, and an electrical plug and outlet to connect the phono motor. The chief engineer must have been a European or a Limey, it is so unlike Philco to do something like that.
Best Regards
Arran

[Arran]

Here's the latest update, I've managed to work on the set for a few nights this week for an hour or so at a time, and the chassis is about 2/3 finished. Out of the paper condensers I've replaced 7 out of the 9 and I am halfway through replacing the bypass one with the RF choke, if that's what it's for?. Strange how Philco constructed these RF chokes, in this case they used a proper cardboard form with the condenser inserted inside the form, and the whole assembly covered with a waxed cardboard sleeve. In others they simply wound the coil with 20-22 gauge rubber covered wire around the outside of a .22 MF, 600 Volt condenser.
Anyhow after this I will be onto replacing the filter condensers, strange enough I managed to reform them while powering up the set on the variac which is surprising since they are the waxed cardboard tube types. Needless to say I don't trust them, I'm not fixing this set twice in one month, so they are still coming out to be replaced with some nice aluminum cased Rubicons. I will let you know how the set works when it's finished, I still need to clean up and repair the speaker.
Best Regards
Arran

[Texasrocker]

Hello Aaron! I wouldnt worry about the cap in the "tube" too much! Philco did some strange-things in ridding unwanted UFO signals in the overall signal-path sometimes,(hee hee), just as you & all us here have "encountered" over the yrs! ( hee hee)! Cut that orig philco rascal cap loose, replace it with a modern replacement, and if in qusetion after that, just cut a small piece of 18 ga solid-strand wire, solder it to one end of the cap, wrap the cap, & your ears can do the rest/test! Personally speaking, I think Philco often times "chunked in" some strange parts ( whatever was onhand) over all the yrs, as did most mfgrs back then, as the orig Philco assembly line workers had avail on any given day! Ive run across "stranger things" , just as you, in many sets Ive restored over the yrs past!
Congrats on your Philco restoration!, and glad to hear you had a 60 hz motor in your phono! Listened to any good vintage records on it yet? Keep us posted!! Your a great asset to this vintage radio forum indeed, keep up the great work Aaron!!!

[Arran]

I though that I should mention that I got the radio playing now, and quite well, what I wanted to know is if anyone has the schematic and voltage specs for the 46-1201 with a voltage doubler, not the version on Nostalgia Air with the typical AC/DC style half wave rectifier. I have the schematic for the Canadian 706A but the voltages are way off, it pegs the maximum plate voltage at 120 which seems out to lunch, the 48-1201 shows 180 VDC but there are circuit differences, a Pi circuit power supply with resistors for example. The voltage I was getting was almost twice that, no surprise for a voltage doubler, I was getting 210 volts at the screen grid and plate of the 50L6, the maximum rating is 200. As I didn't want to burn up the tubes I tried reducing the size of the filter condensers by half to reduce the B+ voltage and it made no difference, still came out at 210 volts. There was a 90 ohm resistor in series with the plate of the first diode of the 50X6 rectifier, it dropped the input voltage by about 12 volts from 122 to 110 AC, since it was burned a bit I replaced it with a wire wound 225 ohm resistor which dropped the input voltage down to 95 volts AC, now the plate voltage is down to 176 volts DC at the 50L6.
However the plate voltage at the 7C6 first audio/second detector/AVC tube is currently running at 140 volts, while the tube manual says this isn't near the maximum in flicking through my Philco service manuals I could not find another set with that high of a plate voltage on that tube, the closest was maybe in the 100 volt range. It seems that 176-180 volts DC is acceptable for the rest of the tubes as I have found similar voltage ratings in other Philcos for the 7A8 and the 7B7, and it isn't out of line for a 50L6 or 50A5. I'm thinking of installing a larger value of plate resistor in series with the 7C6, perhaps a 470k ohm in place of the 220K ohm.
Best Regards
Arran

P.S I did work on the phonograph portion, the motor and idler wheel was seized up from hardened grease, took those apart and cleaned them with varsol, greased and oiled everything, now they spin freely. I believe that the phono cartridge is shot, I hooked it up to the inputs on the radio and didn't get anything, tried checking it with both a voltmeter and an ohm meter but I didn't really know what to look for either way.

[joybird]

What ever became of this unit???


Bob T

[Arran]

What ever became of this unit???


Bob T

 I still have it, it's been sitting in drydock for a few years now. I think I explained on Vecher's 46-1201 thread. Basically I got it to a point where it played but I could not align it in such a way that the dial would track properly. On top of that the phono cartridge needs a rebuild or replacement, I could not get the mercury tilt switch to work consistently, and the platter needs re-flocking. This is just the electro-mechanical side not the cosmetic side, the cabinet needs refinishing and it needs a new grille cloth too. So other things came along and I put the unit aside and never got back to it.
Regards
Arran

[joybird]

I sold mine Regret it

Found this cleaning yesterday.

https://www.flickr.com/photos/jeremyhopk...nqB-dGbMUS


Like new record. Played both sides on my 46-1201-127

The 706 Cabinet made the US Cabinets look sick.   Oak tone color , but I think solid Maple wood.

Bob T

Let me know if you ever want to sell. But Shipping may be costly from Canada

[Arran]

 I think that the one you have a photo of in your gallery was stripped and refinished at one point. The model 706 I have looks exactly the same as the U.S built 46-1201 with the extra dark walnut tone spray on the sides, and control panel, and the "Philcote" faux finish on the rest, I think it's either supposed to be a teak or a quarter sawn French walnut grain. The knobs and the grille cloth on the set linked to have also been replaced, the originals are of the same style as Philco "Hippo" knobs.
Regards
Arran