Unusual Gonset receiving converter

[K9STH]

In today's mail I received a pretty unusual receiving converter made by Gonset. It covers 15-meters, 10-meters, and 6-meters with an output near 6.5 MHz. There is no indication of any model number on the unit.

Doing a "Google" on this converter I find a number of inquiries about what the model number actually is! As such, there are at least several of these converters "out there". All of the photographs that I can find have a green dial but this one is red!

Converters for these bands were fairly common in the late 1940s and well into the 1950s. RME had one for 20-meters, 15-meters, and 10-meters with a 7.0 MHz i.f. as well as the more common VHF-152 series which covered 10-meters, 6-meters, and 2-meters that also had a 7.0 MHz i.f.

Of course, Gonset is much better known for their mobile receiving converters but this particular one is strictly for AC operation.

Glen, K9STH

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[N2EY]

Glen,

WOW! Never seen anything like that! The Gonset heritage is clear, but the round 300 degree dial and such are unusual.

Is it possible these are prototypes of a model that never went into production?

What's the tube line-up?

73 de Jim, N2EY

[K9STH]

Tube line up:

3-each 7K8 loctal tubes
2-each 6BA6
1-each 6AK5
1-each 6X5 rectifier
1-each OB-3 voltage regulator

The wiring, tube sockets, etc., all appear to be general production in that they are riveted to the chassis, the wiring is very professional, etc. However, so far, I haven't found any nomenclature on the converter.

Glen, K9STH

[KL7AJ]

In today's mail I received a pretty unusual receiving converter made by Gonset. It covers 15-meters, 10-meters, and 6-meters with an output near 6.5 MHz. There is no indication of any model number on the unit.

Doing a "Google" on this converter I find a number of inquiries about what the model number actually is! As such, there are at least several of these converters "out there". All of the photographs that I can find have a green dial but this one is red!

Converters for these bands were fairly common in the late 1940s and well into the 1950s. RME had one for 20-meters, 15-meters, and 10-meters with a 7.0 MHz i.f. as well as the more common VHF-152 series which covered 10-meters, 6-meters, and 2-meters that also had a 7.0 MHz i.f.

Of course, Gonset is much better known for their mobile receiving converters but this particular one is strictly for AC operation.

Glen, K9STH

010.jpg

Quite a cute lil' feller. I had one of the more common mobile downconverters..I think it was 80-40-15. Never used it, but it sure was built like a brick outhouse.

Eric

[N2EY]

Tube line up:

3-each 7K8 loctal tubes
2-each 6BA6
1-each 6AK5
1-each 6X5 rectifier
1-each OB-3 voltage regulator

The wiring, tube sockets, etc., all appear to be general production in that they are riveted to the chassis, the wiring is very professional, etc. However, so far, I haven't found any nomenclature on the converter.

Glen, K9STH

Fascinating! A lot of tubes (6, not counting rectifier and VR, which is more than many receivers!) for a converter, too. Perhaps it was an initial production run, like the Johnson Avenger? Seems very very clean.

You have a true rarity there. More pictures, please?

73 de Jim, N2EY

[N2EY]

Quite a cute lil' feller. I had one of the more common mobile downconverters..I think it was 80-40-15. Never used it, but it sure was built like a brick outhouse.

What you had was probably a Gonset Tri-Band. IIRC it covered 75, 20 and 10. It evolved into the Super 6.

Historical note: Until the early 1950s, 40 meters was all CW and 15 wasn't a ham band at all. So ham HF phone was confined to 75, 20, and 11-10 meters. Hence the Tri-Band and similar products.

I had a Super 6, and it was very well built. Particularly compact for the era, too. Wish I'd kept it.

73 de Jim, N2EY

[KL7AJ]

What you had was probably a Gonset Tri-Band. IIRC it covered 75, 20 and 10. It evolved into the Super 6.

Historical note: Until the early 1950s, 40 meters was all CW and 15 wasn't a ham band at all. So ham HF phone was confined to 75, 20, and 11-10 meters. Hence the Tri-Band and similar products.

I had a Super 6, and it was very well built. Particularly compact for the era, too. Wish I'd kept it.

73 de Jim, N2EY

I think you're right. As I recall, it converted to the AM broadcast band so you could use your car radio. Had a really precise worm gear tuning mechanism too.

Eric

[K9STH]

Gonset made all sorts of mobile converters for not only the HF bands but for 6-meters, for VHF public safety, etc. Most of them used around 1500 kHz as the i.f.

Here are a couple more photos. It is missing a couple of shields (have plenty so no problem) and the 6X5 has been replaced with a couple of diodes soldered to the tube socket (will probably go original with a 6X5).

Glen, K9STH

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[KE0ZU]

Actually these are fairly common, originally marketed to be used with the BC348, I understand. My Father and I had one in the late 50's, using it on 6 meters. The three converters are identical, except for tuning circuits of course and the band change is done by switching the filaments. I've looked several times and never have found a model number. Some day I guess I'll have toset down and draw a schematic.

I still have one of these and the BC348 I used in the 50's and later on HF in the 70's on CW.

[KO6WB]

It's the Gonset 6-15. The first showing of it was in Febuary 1948. At least this looks like it. The IF frequency is 7Mhz. It has 8 tubes and it cost $75.00 at the time. In todays value it is $714.29. Kind of makes you think todays prices aren't so bad afterall.
Have a good one
73
Gary