ID this Harris amplifier?

[Opcom]

sorry for the bad pic. This among a truckload of unusual items was in a SK's garage that got cleaned out. This appears to be socketed for a 3-500Z. It has motorized tuning for 10 preset channels. There is a large rotatry switch with a lot fo fixed capacitors on it, a large fixed tapped coil of flat ribbon, and a large variable inductor, not a roller but instead of the wheel it has a 'clamp' than rides the variable pitch spiral square-cross-section winding. I don't know if it fine tunes itself or what.  There are two big Jones-type connectors on the back as well as a 240V twist-lok and RF in and out. No name plates. The top panel has a meter for 0-1000 watts, another meter I think for plate current, ten lights, a 10-position channel switch, tuning up-down for manual use?

I was told it is a Harris.  Inside there are settings covering 2-30 MHz. Can anyone say for sure what this item is and what it is good for?

It is complete, plus a quite large mummified rat found in appropriately the power supply, and a gallon bag's worth of pecan shells, as well as what looks like the top half of a thighbone from a small animal like a dog, and a colorful plastic fishing float. I suppose he kept those items for decoration. The expected odor is there, but it seems like that is very old, and I hope it can be cleaned and disinfected. None of the circuit board "brains" of the amplifier seem to have been affected or played with by the messy old rat, but I could not get a real good look. I offered $100 for it in hopes the parts might be useful and I hope I did not get skewered.

[W1ATR]

Thats a Harris RF-103. Those ran a single 3-1000z toob. I had 2 of them I stripped years ago and made one monster frankenmaul using both tubes. If you can have it for a c-note, there's lots of nice heavy duty goodies under the hood.

[Opcom]

wow. I got a 3-1000Z sitting in a cabinet here. Maybe.. OK, well if I get it, I can't go wrong then.

[W1ATR]

Yeah they weren't a bad amp, just a pita to work on. My two were parts beaters so I had no reservations about taking them apart to make something else, (and something else it was indeed, lol) That roller inductor you saw in there is the big Johnson flat wound, dragging contacts, 25amp job. Real QRO 

[KC2YOI]

I have dibs on the mummified rat   .....

Looks like a solid start to there, w/ good band cvrg built right in.

                                                   D

[Opcom]

OK I can get you the rat if you want him. He was in pretty good shape considering, with only a couple of burn holes underneath. His toys as well (no extra charge). I need to call the guy and have him get the rat off the lawn where he got pitched. We already discussed dipping him in varnish for posterity. Hopefully he has not become a potato chip for a stray dog.. You have to pay shipping though. PM w/ contact info and address if serious, but do it soon!!

I wonder if the amp can be pushed down from 2MHz to 160M?  well it is a good chance it is a parts unit anyway

[W3SLK]

I don't know how much it pertains to it but.... I have a RCA SB-1K which uses a pair of 3-400Z's @2800VDC. Its a radiomarine job but it has no trouble loading up on 1900 with plenty of head room. I even ran FM on 160 with it just for kicks. Pi-L output tank.

[w4bfs]

also got a harris hf103 ... it does not appear to be an auto-tune but rather a preset tune (several per band) ...if you get stuck for a manual, let me know .... reckon you will cathode mod this un ? ...73 ...John

[Opcom]

I'd thought about trying to put it back together for normal use, but who knows.

I cathode-modulated a 250TH before, I suppose I could do it. I have only the BAMA manual, which is incomplete but usable and has some 160M conversion notes, but the reproduction is rather poor. I can see that it has quite an electronic brain.

I don't see the filament return. I must be missing it or the manual is not complete enough. I am puzzled by the schematic showing the filament CT going through a 100K 25W resistor R16 to ground. Maybe that is a misprint. I don't have the amp yet.

Thanks,
Patrick

[ke7trp]

Thats a Brute of an amp.  I have the Harris AM1000.  It uses a single 1500 tube.  Its auto tune and load and you can make a board to interface with modern radios.  I have not tested the unit yet as TFO is making me a new interface cable. When it was removed from service the military CUT all the cords off flush with the units.

The big trouble that unit you have and this one is that the blower motors are as loud as a wet/Dry shop vac running in your radio room.  It will need to be remote mounted somewhere.

C

[Opcom]

It can't possibly be louder than the amplifier unit of an AN/GRC-106A. The only thing louder that a GRC-106 is the 2.5 ton military truck used to haul the shelter it is mounted in. Or a shop-vac in a tornado.

[John K5PRO]

Yep, an RF103 it is, with the single big tube. The preset tuners are not much use, but the parts are worthwhile to repackage. The big tapped inductor with a motor is kind of neat for an antenna tuner. I stripped one for parts years ago. The plate transformer in that amplifier is good for higher voltage, such as a replacement for a Chippewa (which is what I wanted it for).

[Opcom]

The bottom line is I offered $100 for it, and figured someone else would offer more, and I lost that bet alright.

I finally got it into the lab and it is sitting on a cart. Boy is it a rat-pee smelling contraption but it seems complete and I have not found any chewed wiring. The rat died while measuring the HV I think. I don't know if I can get the odor out or not. I will remove the door and outer case, there is a lot of 'stuff' down in the bottom of the side panels. I have to wait till it is not 105 degrees and do that outdoors.

I hate to think of dismantling it because it looks like a real solid and high-duty amp, but no one will want it if it smells, no collector would want it. If I repackage, I could clean up the brains and sell them off to someone who needs spares.

That inductor is about 22uH if I am right. Could it handle two 3-1000's (or 3..)?  - see but that is nuts as I already have a 3CX3000 amp.

And the huge ceramic switch with all the caps on it - that thing is great but it has so many decks, what would be a good re-purpose?

- try and get it working before deciding -just to see what happens.

[W2VW]

Ammonia will clean out the scent. All you have to do then is wait a few months for the ammonia scent to go away.

[Todd, KA1KAQ]

Ah, yes - the mouse/rat pissolene smell as Timmy would call it.

I remember seeing Tim looking over a CE 200V years ago at Hosstraders in Rochester NH. He was supposed to get the 32V out of the pile, but his pal the HODman sold it to someone else. So he pointed Tim to the 200V and opened the lid. Tim leaned over, peered inside, then sorted jumped or leaned back rather quickly and said:

"There's a MOUSE nest in there. That means mouse pissolene. I don't want it."

Talked Brian, 'LYD into buying it and he said it cleaned up fine.

[KD6VXI]

You ever get your RF103 working?

Just restored mine, wondered if you parted yours, or you got it working.


--Shane
KD6VXI

[Bill, KD0HG]

The loudest TX I have ever heard was the AM-3924 linear, part of the Navy URT-23. 1970s era HF rig using early spread-spectrum crypto technology.

Pair of 4CX1500s in a broadband linear setup. Loafed at less than 1 KW PEP output. Driver was a pair of 8122s. The whole linear package would take you from the few hundred milliwatts of the T-368 AM/SSB/RATT transmitter to a full KW output, no tuning needed from 2 to 18 MHz.

Specs included being able to fit through hatches on a submarine.

You definitely needed hearing protection of some kind when running the thing.

[KM1H]

The Collins 648B-1 could compete for the loud award. It was a airborne UHF amp used on the Looking Glass aircraft. It ran as a wideband AM linear at 1000W out using a GE  GL-51064 tetrode with a 2750W Pd.

The tube makes a lot of RF on 432

Carl

[Opcom]

Have not messed with the Harris RF-103 yet. The antenna took precedence, but maybe it would be a good idea to clean it out and see what it will do. Might also be a good idea to sell it off or part it. The variable inductor from the plate circuit is interesting looking. If I can get the 3CX3000 amp running I might not care to mess with the Harris.