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Trusted Site for Used AM Transmitters?

You can justify it that if a module blows, you're still on the air at (albeit) reduced power. Better than being off the air. No tubes to replace. Do the math for efficiency of your CSI tube unit and, say, the Nautel and then you can show him the electricity savings. Remember to do AC in to RF out efficiency calculations, not just PA efficiency, as that doesn't factor in the other innards, such as filaments etc. that are running/blowers and the electronics/blowers in the SS Tx.

The CSI can also be relegated to aux duty, so if a module blows you can stay on the air at full power or use the SS at half or 2/3 power, depending on the PA configuration.
 
BobOnTheJob said:
Kent T said:
The DAX series has a lot of Surface Mount components on that main board. Not built to be field serviceable. Not recommended. The Gates One and Five are good transmitters, if a bit complex on troubleshooting. I would avoid Harris MW and SX line due to support from Harris having ceased for all intents and purposes.
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If anyone wants an MW1 in Indiana, make any kind of an offer and come get it.
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And I have one in Kentucky, too.
 
I know of someone that just gutted some parts out of a MW1 just to build a new ATU. That might be the best use for one. What a dog those transmitters seemed to be!
 
OKCRadioGuy said:
I know of someone that just gutted some parts out of a MW1 just to build a new ATU. That might be the best use for one. What a dog those transmitters seemed to be!
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It was a good transmitter as long as you didn't drive it too hard. I know of a couple of stations that have them. One is 500 watts and the other is 250 watts. They have had them forever. However, if you ran it near it's rated power, the lifetime of it was not near as long.

It was the first PDM transmitter Harris built, which is all the information I needed to stay the hell away from it until they got the technology figured out with the SX series.
 
OKCRadioGuy said:
I know of someone that just gutted some parts out of a MW1 just to build a new ATU. That might be the best use for one. What a dog those transmitters seemed to be!
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Would that be a female dog by any chance?
 
not to get too far off topic here but what are the real power savings of SS vs tube at the 1kw level? I currently care for an old CSI 1kw tx that just runs and runs and runs... It surely can't make 125% positive, more like 110 on peaks but it does still sound good. I of course have to stay on top of it to keep everything in good order.

What are the real advantages to going SS? How would I justify it to an owner that likes to pinch pennies?
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At 1 kW you'll see a dramatic reduction in the transmitter power bill. I replaced a Gates 1-F with a Nautel ND-1 at a site with no AC, just forced air. Power bill dropped from 250 to 90 bucks a month. Add that savings to what you save by never having to buy tubes and the SS rig will pay for itself in time. The increased modulation capability is a nice bonus.
 
I have been replacing really old tubers with Collins 828/Continental 315R-1..Both great boxes for cheap if you have a bit of patience for the set up and parts are a breeze to come by...
 
What about running solid state with no air conditioning? What kind of environment do they expect? current site is a metal shed with an exhaust fans and filtered vents to let air in. It gets pretty damn hot in there in the summer, the old CSI just keeps on running and doesn't complain, as does the omnia one... If it needs some cooling, that would surely cost more in electricity than any savings...
 
At 5kw I am not sure of trusting just any old used transmitter. The Rockwell is always something that still has support.
 
stephend2 said:
What about running solid state with no air conditioning? What kind of environment do they expect? current site is a metal shed with an exhaust fans and filtered vents to let air in. It gets pretty damn hot in there in the summer, the old CSI just keeps on running and doesn't complain, as does the omnia one... If it needs some cooling, that would surely cost more in electricity than any savings...
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Ideally, you want some air conditioning with a fresh air intake as backup should the air conditioning unit fail. With a solid state rig, you don't need as much. However, if you are gonna run just on a fresh air system, make damn sure the intake filter to both the building and transmitter stay clean and the inside of the transmitter stays clean. If the filters get clogged and/or you get dust and dirt in the cabinet and the transmitter start overheating, you'll have major trouble and expense getting it right again. Solid state units are not as forgiving on filth as tube rigs are.
 
On that used 5KW, Continental is a good choice. The 315R-1 is a good box when set up well. And is usually reliable and supported very well by Continental Electronics. Who is my favorite vendor for supporting their oldies. A good buy!
 
The Power Rock 5KW rigs still sound very good, modulate well, and Continental still supports them for parts. They were designed by Collins Radio by top engineers Jack Sellmeyer and Forest Cummings.
 
I'm running a solid state FM rig at 3kW with 15,000BTU of cooling... it vents right into the building, which is 8x12x10. It stays 66-68 degrees inside even when it's 95 outside. The electric bill in August was $351 for the month. That's running 3kW on an FM, which is much less efficient than the AM SS counterpart. You're running 1kW, wasting less heat. So your AC requirements might be smaller as well.

One thing I would recommend with your metal shack is to insulate it on the inside if you do go the SS and air-conditioning route. That helps keep the heat out of the building in the first place.
 
Too bad Harris doesn't support their older stuff like CE or Nautel. I love the design of some of the older things like the Gates One, Two, etc. but that's certainly a consideration. When you want to get one, even as a backup, that's a concern. And, yes... The MW-1 WAS a female dog indeed! LOL!
 
So, one of my clients has their first rig (Raytheon RA-1000 from 1948) in the basement as their backup. Their previous main, a MW-1, is in storage...it was removed from service 6 years ago because of a power increase (new main TX is a BE AM2.5). Some spares are available in-house for it.

If I suggest the owner sell one of these beasts, which one goes? I just started working for this client a few months ago, and I haven't had the guts to fire up the Raytheon yet.
 
If the load is 50 j0, the MW will perform admirably. If it isn't - a not uncommon circumstace in Class D stations - it may not. Fire them both up and choose. There's no magic at all in the Raytheon, but tubes are getting harder to come by.
 
Paoli Indiana had an old Raytheon maybe Bob can comment if it still runs. Not impressed with Harris support. 5 years ago I remember sitting at a transmitter site waiting on a callback from support in an off air situation. Parts at that time were easier to deal with. They were always happy to sell you a part but you needed the exact Harris part number, from support who could care less about your needs and being off air. Not all stations ahve the book and those that do don't have all the pages. I spent a week at another transmitter site trying on a daily basis to reach Harris. It took 3 days in an off air situation to even get a call on my cell. If I get an older Harris I am happy to keep it running without their help, on FM.

The Gates one is an SX 1 RF without the computer motherboard that the SX series had. In old west terms: If Harris were selling horses someone would have shot them by now. A station bought one because Harris couldn't supply the capacitors for the top of the old SX. Then I get he new transmitter, 10 years ago, and the same caps are in the top of the Gates one. The Gates one knock on wood hasn't needed support except for 5 I installed that ALL had blower sensor problems. In the first case I learned how to wire around the blower sensor on my own as there was no problem. When the new part showed up, it was bad also. Each time I called support they had never heard of that problem. I finally said "cut the crap and look at station A,B,C,D." No telling how many had problems.
 
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