Airline (Montgomery Ward) GSL-1079A Battery Pinout?
 

I recently got a deal on an Airline GSL-1079A (a AC/DC/battery tube portable AM/shortwave radio, similar in circuitry to a Zenith Trans-Oceanic, only with two bands - AM BCB and general coverage 6-18 MC, eliminating the need for the huge coil tower) at a hamfest for $15.

I want to power it up with batteries to try it out. It uses 9V for the "A" and 90V for the "B" battery - just like a T/O.

The battery connector has three wires, which are black, green and red. The logical guess is that black is common-, green is 9V A+, and red is 90V B+. However, I don't want to leave that to chance.

Also, it does use the "unobtainium" 1L6 tube. I would like to try it out with a 1R5, which is known to be a "safe" sub on the AM BCB when one wants to try our a T/O. Would a 1R5 also be safe in the GSL-1079A?

Sams 294-2. I looked, unfortunately don't have it :(

I'll look at my Sams library to see if I have it.
The radio is made by Sonora for Wards, circa 1954/55. I still have one somewhere. I even had one with the Sonora branding.
Regarding to 1R5 sub, it didn't work in some sets, as there is two common pins on a 1R5, that the 1L6 doesn't???? Someone stated that, ages ago,I never tried it. They stated that you had to clip that pin off the tube. :scratch2:

For reference:


http://www.videokarma.org/attachment...1&d=1467904555

Zenith made a plastic AM/single SW band set that used a 1L6, and it unlike the Transoceanics will NOT work with a 1R5 sub....IIRC the heater wiring is shorted with the 1R5.

They made an AM only radio that used a 1L6, a big five tube portable.
That's probably, the one I remember.

I remember being at an old radio swap, circa 2000, and seeing a relatively small Zenith portable (smaller than a GE 637), maroon in color, that had the tube complement 1L6 -> 1U4 -> 1U5 -> 3V4, though there did not seem to be anything "special" about it.

Well, the question about whether or not the 1R5 can be substituted for the converter has been answered, as a previous owner has done exactly that (I do have a 1L6 ready for use if the rest of the set works well).

This radio may be newer that I had thought. Four of the tubes are branded "Wards Airline" and two of them carry the codes "62-09 188-5" (Early March 1962, Ken-Rad). Interestingly, Sonora had gone out of business in 1956, so I wonder if someone else took up production of the same model to supply Ward's.

The radio seems to be put together well enough. Unlike the Zenith Trans-Oceanics, this radio has shields over the tubes (except the 3V4 audio out), which connect to chassis via flanges surrounding the tubes.

While the non-bandspread tuning is generally considered a handicap, I can "tune by ear" fairly well and I should have access to the 22m (13 MHz) band.

I have found some other radios that appear to be "clones", so it may be possible to find the battery pinout in other Sam's folders:
344-6
356-11
417-4

Guess I might make a trip to the library.

Sonora was back by '61,'62 as Sonora Corp. America but Trav-ler produced their products, there was a Trav-ler model as well. By the by, Sonora is still around just not in electronics. All the best, Tom

I've been listening to this radio on batteries lately. Red is B+, black is a common, and the radio works with A+ on green (haven't tried red B+, black B- A+, green A-).
The radio seems to hold its own in a side-by-side comparison with my Zenith H500Y, except the top of the SW band where the Zenith is better.
It will need an alignment -even the AM band is off about 100kHz at the top (possibly realigned by whoever had put the 1R5 in it. SW did not work at all with the1R5, and I've replaced it with the proper 1L6).
Still don't have a schematic for it yet.
It shouldn't be too hard to restore house current operation, as the values on the electrolytics are marked, and diodes easy to acquire.

So, I recently saw the schematics for this radio at a library, placed the radio on the bench and started probing it.

First thing I found was that a 100 ohm power resistor opened up. This is literally the first component to see direct current.

Further work showed that it could play fine on AC by jumping the resistor. The selenium rectifier and the lyrics seem to be fine after all these years.

Disappointment came when I jumped the bad resistor with a new one 100 ohm resistor instead of a near-zero ohm jumper. Silence. I then determined that the oscillator will oscillate using the jumper but not using the 100 ohm resistor. A further test showed that briefly jumping the resistor will start the oscillator and it will continue to run for some time after the jumper is removed, but is prone to suddenly stopping. I've tried different tubes in all stages of the circuit with different results (using 1L6 as well as 1R5), but none are delivering reliable results.

This is weird, Where could I go from here?

I would first locate the top of the filament string, and measure the voltage there. See if it's signifigantly lower than when running on battery. If it's lower, look for a large value, low voltage electrolytic (possibly one section of a can) serving to filter the fil. string. If that cap were leaky it could be dragging the voltage down.

I was gonna say, just hook each wire to 9v, and whichever lights the filaments is A lol

:eek: Yikes!

Dude. Hook 9V to the wrong spot in the string, and you can definitely blow a filament or two. Or three. (That's assuming your 9V is a 'hard' source like a battery, wall wart etc.)

Thanks for the input.

I think what I will do next will be to replace all four units of the lytic (perhaps they are filtering out the ripple as they should, but allowing electrons in the B- to flow to + as they shouldn't), and DeOxit the pins of the 1L6 socket and the bandswitch.