External device to combine two Linear amplifers out to a single antenna?

[jtrouter]

Question, As the title says years ago i bought a box from D&A that has 2 SO-239 sockets marked for Amplifiers and 1 that says antenna.
I belive its to allow 2 amplifiers to work together to increase the power output. I have not seen any being sold before or after i bought them.
Have any of you ever seen or used one? Of the top of my head its painted in the later D&A colors of brown and black trim, about 2 inches tall
and about foot across. I can post a couple of pictures later on this afternoon if needed, Just have to dig it out of the garage. I have wanted to test
it before but without any more information i have no desire to destroy a couple of tube amplifiers to test it out. I look forward to hear from you all.
Thanks for reading.

 

[AudioShockwav]

Question, As the title says years ago i bought a box from D&A that has 2 SO-239 sockets marked for Amplifiers and 1 that says antenna.
I belive its to allow 2 amplifiers to work together to increase the power output. I have not seen any being sold before or after i bought them.
Have any of you ever seen or used one? Of the top of my head its painted in the later D&A colors of brown and black trim, about 2 inches tall
and about foot across. I can post a couple of pictures later on this afternoon if needed, Just have to dig it out of the garage. I have wanted to test
it before but without any more information i have no desire to destroy a couple of tube amplifiers to test it out. I look forward to hear from you all.
Thanks for reading.

Abe Brewer ( varmint ) built a solid state amp that had two amps in one housing, each was in a 1 driving 4 combined together, that is the only amp I have ever seen with that setup.
From what you describe it sounds like a outboard combiner like they used.

Pictures would be great, would be awesome to see the inside

73
Jeff

 

[jtrouter]

Abe Brewer ( varmint ) built a solid state amp that had two amps in one housing, each was in a 1 driving 4 combined together, that is the only amp I have ever seen with that setup.
From what you describe it sounds like a outboard combiner like they used.

Pictures would be great, would be awesome to see the inside

73
Jeff

Ok, i will post a few tonight, i do not remember if i had been inside years ago but will do the
best i can.

 

[jtrouter]

Ok, i will post a few tonight, i do not remember if i had been inside years ago but will do the
best i can. here are the pictures

 

[144inBama]

Looking at the design, in my opinion, it's an oversized splitter. 1 radio (antenna input) driving 2 different amps, using 2 different antennas (or same antenna with a switch). There's no way you could run 2 amps into that setup without blowing up everything.

 

[Captain Kilowatt]

Looking at the design, in my opinion, it's an oversized splitter. 1 radio (antenna input) driving 2 different amps, using 2 different antennas (or same antenna with a switch). There's no way you could run 2 amps into that setup without blowing up everything.

I disagree. It clearly shows two amp connections into one antenna. That is an ANTENNA port not a TRANSCEIVER port. It is only made of precision(?) cut lengths of coax cable to properly phase the outputs of two amps. As long as the two amps are identical it should be alright as long as the total power output does not exceed the rating of the cable.

 

[144inBama]

I disagree. It clearly shows two amp connections into one antenna. That is an ANTENNA port not a TRANSCEIVER port. It is only made of precision(?) cut lengths of coax cable to properly phase the outputs of two amps. As long as the two amps are identical it should be alright as long as the total power output does not exceed the rating of the cable.

I guess I don't understand that theory.... at all. To me, It would be like keying two identical radios at the same time into a single antenna. It seems as though you would be "feeding" RF into the output of the other or both.

 

[Captain Kilowatt]

I guess I don't understand that theory.... at all. To me, It would be like keying two identical radios at the same time into a single antenna. It seems as though you would be "feeding" RF into the output of the other or both.

That is why the coax cables are cut to a precise length. They allow a degree of isolation. No different than the combiner inside an amp electrically.

 

[144inBama]

No different than the combiner inside an amp electrically.

And now it makes perfect sense...Thank you.

 

[AudioShockwav]

I think it was early early Davemade amps were built like this using coax as combiners.
I remember seeing long lengths of coax in the bottom of the case.
I agree with Capitain, the two amps would have to be real close in output for this to work.
I would be great to see the paperwork that came with this, first one I have ever seen.
Thanks for the pictures, I doubt we will ever see another one.

73
Jeff

 

[Dmans]

Wouldn't you need two of these "Precision" devices to use it? You still have to split the output of your "Driver" to each amp input.

73
David

 

[Enterprise312ok]

burning down the house with 2 kl203p, dont turn on both preamp though

 

[nomadradio]

You still have to split the output of your "Driver" to each amp input.

Sure do. Would take two boxes to do this trick. One on the input and one on the output side. The "Dul-Com" box shown is only the output-side half of the proposition.

Heard rumors of this thing for decades, but this is the first one I have seen.

73

 

[Beetle]

Navy shipboard HF gear used "multicouplers" to enable as many as four 1KW transmitters to use one antenna simultaneously on four different HF frequencies and modes. Frequencies had to be plus or minus x % apart and a whole bunch of other "...Oh, by the way..." warnings. They did work, however. Sending official traffic from the middle of the South China Sea to Iceland, Thurso , Scotland and even the U..S.Naval Attache's comm office in Punta Arenas, Chile! Wouldn't count for a midwatch Worked All Continents.

You'll note I didn't even try to spell the capital city of Iceland (Reykjavik).

 

[928bolo]

Acom makes an HF Power Splitter/Combiner for three amplifiers. Three amps into one antenna. DX Engineering sells it. $3,199 5kw max power.

https://www.dxengineering.com/parts/aom-a3x2000

SPE also makes one for two amps. $2,395 5kw max.
https://expertlinears.com/products