Harris SX line

[kyscott]

Just curious. What do you think the life span should be? At our company they project transmitters at 5 year amortization, 10 year real use, and anything over 12 as being good luck.

If you expect a transmitter to last 10 years, you are short changing yourself. When a transmitter reaches 20-25 years I tell the client to start budgeting for a new one. I had a client that had a Bauer 707 that had an output cap puke, it was going to take them a week to get us a new one. The Bauer was my age, 40. it was time to replace it. I had a Harris FM25K that was a great transmitter, had a loud ass fan, but a great transmitter. It was installed in 1985. It was a good transmitter, never had any problems with it, the last three years I worked for this company I was telling them we need to start budgeting for a new transmitter.

 

[littlejohn]

The 707 was a hoss. Was yours kit built, or the "Factory Assembled" model?
In re the 25K, we differ. I had S/n about 5, I think, and nothing but trouble. It wasn't the worst I've even seen, but only because I was blessed with a 40K at one point which had been field assembled from an older and a newer 20K. The power vaults make great boat anchors though.

 

[kyscott]

The 707 was a hoss. Was yours kit built, or the "Factory Assembled" model?
In re the 25K, we differ. I had S/n about 5, I think, and nothing but trouble. It wasn't the worst I've even seen, but only because I was blessed with a 40K at one point which had been field assembled from an older and a newer 20K. The power vaults make great boat anchors though.

I don't know about this Bauer, I think it was kit built. It was a good transmitter, and I'm trying to get them to let me either replace the capacitor and let's use it as a stand-by transmitter, or load it in my truck and bring it home with me.

My 25K was a little bit older, the SN was in the three digit range.

 

[littlejohn]

If it had a three digit serial, it was newer. 5 a as in the fifth one to leave the Tinworks. With none of the mods in it, most of which I stuck in it until I could get rid of the thing. The most obscure one - and one which required a 3 ayem call to the factory - was a change in the harness in the power vault. The original ones would inhibit plate on if the gollyrod wasn't in the clip, but wouldn't light the HV CAB fault. So, no go, but no fault light. After several hours of working around an open drop solenoid, then it won't run.
Whenb I replaced it with a pair of Continentals, and advertised it for sale, Harris bought it back. i don't think theu wanted their newest and latest on the used market, and they dam' sure didn't want their potential customers aware of my problems with the thing.

 

[kyscott]

Whenb I replaced it with a pair of Continentals, and advertised it for sale, Harris bought it back. i don't think theu wanted their newest and latest on the used market, and they dam' sure didn't want their potential customers aware of my problems with the thing.

No, I didn't have those problems with mine. The only issue I had was I had to replace the IPA with an outboard Silicon Amplifiers box. I have noticed that happening with Harris alot recently. First few runs of a transmitter line having major problems like that. I'm assuming they have cut back on their research and development team. They come up with an idea, and throw it out to the market and let the first few owners of that new transmitter line work out the bugs for them.

All the more reason to avoid Harris now.

 

[littlejohn]

Well, I have to grudgingly credit the Tinworks:
Yesterday we finished the plumbing and wiring on a new HT30-HD. We were given it over our prference for Another Brand, but hey - new toys are new toys. At any rate, checked everything, fired up the filaments and confirmed 10 volts, and then did the 'How do ya feel, Punk? Lucky???" approach and hit the go button. For the first time in over 40 years of dioing this, a Harris radio came on and ran with every parameter within 5% of the test data sheet excepting the power meter cal. It wanted a turn or two to match my Bird meter. In that a) there's a lot of shifting around hooking and unhooking the sample section and its diodes; and b) there may well be a difference between a calibrated Bird into an Altronic load and a factory run into a calirometer, I don't find this difference surprising. They are improving.

Today I will take a swept analyzer and see if the thing meets the mask when the HD is on. And we'll se how much tweaking it wants to minimize the IM and how stable it is.

I'm still no great fan of Harris or their business practices, but it looks like they at least got someone in the back shop who had the desire to send this one out working properly, rather than simply getting it on a pallet and out the door as my previous experience has indicated.

 

[kyscott]

I'm still no great fan of Harris or their business practices, but it looks like they at least got someone in the back shop who had the desire to send this one out working properly, rather than simply getting it on a pallet and out the door as my previous experience has indicated.

That was a mistake. The rig was meant for someone else. ;D

The only transmitter I have been able to do that with has been a Nautel. I have never been able to set and turn on a tube transmitter without doing some serious tweaking and tuning. You should mark this down on the calender, it's a red letter day!

 

[BobOnTheJob]

One of my clients uses a 37 year old CCA 20KW box at 7KW and I haven't asked him to budget for a new transmitter. Why? Because nothing out there is going to be as reliable. When it was running 8KV on the plate as a full B, it would lose a plate blocker ever year or so. With less than 5KV as a B1, it's using the same blocker it used since 1985. It gets a bath once a year & tubes as needed. I hope I don't jinx myself, but it has been the better part of 10 years since anything actually failed to the point of causing lost air time. I can fix old CCA's with my eyes closed (slight exaggeration) and parts can be borrowed here and there. With this rig, there are no microprocessor boards or power modules to have overnighted. Back to the future works best in this case...

 

[OKCRadioGuy]

You know Bob, I can appriciate what you're saying about simple transmitters. I have a friend that has an old Energy Onix FM transmitter that I had to help him with last week due to water damage, etc. After getting the water out of it, cleaning up everything, and letting the blowers go for three days it just fired right up and worked. He said it's the first time he's had ANY major failures other than tubes that went soft. He's had it for over 15 years. I was impressed. When I first saw the thing I thought "what the hell is this P.O.S.!?" but one has to wonder if simple IS the best idea when it comes to RF boxes.

Harris seems to be one of the worst when it comes to protecting the transmitter to the point it takes a station off more than it needs to be, also adding to complications when trying to fix it.

 

[Tube Shortwave]

Every time I see a HArris, I think to myself "A computer connected to a lightning rod". The best 'old' rig in my opinion is the Collins, then Continental 816 series. Second choice is my old RCA BTF 20! Boy that thing was dirt simple. You needed sunglasses and earplugs to troubleshoot it, but it was super simple.

 

[OKCRadioGuy]

Ahhhhhh! The RCA Fireball Series!

Home of the self-combusting Lucite!

I'd MUCH rather have the Collins/Continetal rig!

RCA, The most RUSTED name in electronics. "Where's my hama! Iz need to re-adjust this here transmitta."

KAPPPPOWWW!!

 

[littlejohn]

I'd take the CCA over the RCA anytime. Fewer internal fires. I'd hate to have to hang my hat on either one running at rated power for any length of time. But, the CCA will do whatever it will do with less histrionics and fewer busted neutralizing caps, seeing as how it ain't got any.
I pulled a BE 30T out for the HT, it had run flawlessly save for a driver power supply problem I created via ignorance. It went ot another station to sit beside its mate.
Did the preliminary look at the HT, looks like it meets the mask with the RTAC running. Without, forget it. I have to get the mask on the analyzer and take some pics for posterity and the FCC letter. Week after Xmas it is. Anybody got a file to generate the HD mask on an Advantest swpet analyzer?

 

[scappy]

Every time I see a HArris, I think to myself "A computer connected to a lightning rod". The best 'old' rig in my opinion is the Collins, then Continental 816 series. Second choice is my old RCA BTF 20! Boy that thing was dirt simple. You needed sunglasses and earplugs to troubleshoot it, but it was super simple.

We still have one in backup service at WMRV. It ran until 1999, when it was replaced by a BE FM-20T. Everytime I hear of someone parting one out, I grab up as much as I can, and then "upgrade" anything that's getting worn out or drifting in tolerance.

 

[FredRichards]

I'd take the CCA over the RCA anytime. Fewer internal fires.

Are we talking AM or FM?

I never had problems with RCA AM transmitters, and I even had a dreaded (pause) Ampliphase.

But the FM transmitters were stinkers. In the FM10E and 20 I had, both had issues with finger stock, tuning (staying put), and also the black rectifiers on the rear of the cabinet.


Fred (presently turning an ITA 1000 into a ham rig)

 

[Tube Shortwave]

The trick to tuning the RCA (to avoid replacing fingerstock) was to tune it at about 20% power. When everything was where you wanted it, you shut it off and opened the PA cavity. Then, use a level to position the fingerstock exactly level. Then, close the cavity and DON'T TOUCH!. Run the rig up to TPO and touch up the driver plate tuning and PA input tuning, but don't touch the PA tune or load. Never, NEVER tune the PA cavity while running full power. That was asking for trouble. Oh, and invest in a case of Tarn-X too. You use a lot of it keeping an RCA on the air.

Of course, the RCA only gave 66% efficiency, and when the PA tube was done, it looked like it was in a BBQ pit for a year, but at least it ran. I didn't have to work on one much past the early 90's. Retired now, things back then seemed less trouble prone than stuff now. Might be faded memory syndrome.

 

[littlejohn]

I was talkin' FM. But the little CCA AMs did all right.

My shiny HT HD is true to form, though. Puked up and quit Xmas eve. Sigh.

 

[RadioFixerCLE]

Every time I see a HArris, I think to myself "A computer connected to a lightning rod".

That certainly is an apt description. Tom Ray showed me WOR's new Harris transmitter -- I forget right now what model he uses -- and it was basically that. Totally solid state, which was amazing in itself -- I always visualized these iron monsters with rows of hot, glowing vacuum tubes that you could see through the glass panels in the front doors.

WOR's rig is essentially a huge metal frame with big printed-circuit boards sliding in and out. One of those modules goes down, you just swap and replace. The old board gets sent back to Harris for repair. God help you if those parts get discontinued, though.

 

[Bill981]

Tom has a pair of Harris 3DX50's. As with any solid state box, the FET's are the most vulnerable part. I had a 3DX50 in Tampa (lightning capital of the world) and had two modules go all summer. I sent one to Harris for repair. $450 + $12 worth of parts. I decided then to do future repairs myself. Got the parts from either Mouser or Digikey. Harris has a manual on their premium (free) site on how to check the xstrs with a DVM. I checked their "good" readings against a working module, and they were close enough. The 1 ohm SMD reisistor is the hardest part to replace, and even that isn't too bad (with a magnifying light.)

 

[Tube Shortwave]

The 1 ohm SMD reisistor is the hardest part to replace, and even that isn't too bad (with a magnifying light.)

1 ohm? I would replace that with a solder blob!

 

[RadioMan203]

That's my only fear with a solid state rig - getting fried by a lightning strike. I've seen some of the older vintage microprocessor controlled transmitters throw a hissy-fit after a strike and it seems they hardly ever give you any way of getting the box back up without the assist of the control electronics. The MW-1 at the AM I had was pretty good in that respect, but of course this was before microprocessor control - I'm talking strictly suffering from lightning now.

All I have to say is if you have a Harris box you'd better stock up on parts while they're still in production unless your station actually budgets for transmitter replacement. The last thing you need is a midnighter at the shack only to discover you don't have that one key part to put the rig back on.