The AM Forum

FYI, that Gates BC1-G mentioned in the ebay links section here sold (apparently for the second time up) for about $227!! It was in Greenwich, Ct.

I certainly considered bidding, but my personal situation would not give me enough free time to go and get the beast. <Boo Hoo>  Shame that. Finally a monster rig shows up nearby, and I can't do anything about it. Grrrr...

Cheap enough, eh? The tubes alone cost more than what it went for. Wow.

http://www.ebay.com/itm/251736184499?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/251736184499?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

                            _-_-

The BC-1G is a very good transmitter.  Whoever got it really got a good deal on it.  Lets hope they put it back on the air and have some fun with it hopefully on the Ham bands. 

Lately the BC rigs have gone pretty cheap.   It wasn't that many years ago that folks were paying 1500 or so for a rig in good shape.  Now a lot of stations seem to be almost giving them away. 

Joe, GMS       

Don’t think I would have paid that much or more if it was local to me, and with having to spend five hundred or a thousand dollars to go pick it up and everything you got to really want one. I tried to give away two or three transmitters including a cleaner BC-1 several times and the same scenario would come up, the person would be all excited until they learn that it weighs over a thousand pounds and they have to remove it. Still over the years have managed to give away at least three and picked up a RCA-BTA1MX that I spent several hundred hours on rebuilding and installing in the shop with an old General Radio modulation monitor and Volumax processor all running on 1.885 but in reality have only used it a handful of times and have thought of selling it but although I paid nothing for it the thousand or so dollars that I would want for it is way beyond what anyone would spend, so I am inclined to think there are more transmitters on the market then there are Hams who have the capabilities to use them and unless it’s a Collins 20V that for some reason people think is so special the days of big money for old broadcast transmitter is over. Then again it can just be me, have noticed anything that I want is always more expensive then it should be but after I buy it it’s somehow not worth much at all. That’s the story of my life when it comes to buying and selling this stuff, buy high and sell low. Buy broken and spend more on part then the cost of a working unit, things like that.

Fwiw, Greenwich CT is within driving distance for me. I think that it would have taken the better part of a full day to get there, disassemble the big I-Ron, and then load the beast into my van, drive back and unload. Not that much of a big deal. A helper would likely be needed...

Making it run on a ham band is an entirely different story.

Personally, I don't find the BC1-G to have a particularly "eye-candy" look. So, assuming I had one, I'd probably opt for "repackaging" the important guts into a more compact form. That, of course does not account for the many hours involved with this or any DIY project.

Ymmv.



 

Take the mod iron and make the rest into a boat.

People always say u can't find mod iron.

My thoughts too... the Iron may be well worth the money!

Moving a thousand pound unit should be easy.  This summer I sold some of my heavy machines and the buyers came with the right trucks or trailers and we loaded them with no problems.  They were 4000lbs, 3800lbs, 1800lbs, and 1700lbs. Attachments and other parts probably over 2000lbs.

Thousand pound xmtr, piece of cake ;D

Fred

I know the guy who sold that transmitter.  Didn't know about it until this post.  He never said anything about it on the air!  Not that I personally would have been interested, except maybe for the parts, but there are a whole lot of AMers in the North-East who would have been interested.

Usually when I see a transmitter like that for sale, it is a thousand miles or more from here and with a high price tag.

Broadcast MW AM is circling the drain. Plenty more to come.

I would like one more shot at one............but for free or reeeeel cheep.
I regret the other BC boxes that have slipped through my hands. It's not fun when they can not be in the shack and hear them humm when using it.
Fred

Looks like you have another chance, just saw it on QTH. Relisted this morning

                                              ****************


 FOR SALE Gates BC1G Broadcast Xmtr   1 KW Broadcast Xmtr (2) 833's modulated by (2) 833's $250. Xmtr located
in Greenwich, CT. and must be picked up by 01/05/2015. email for more info and additional pics.Tnx & Vy 73, KA4NNN. Listing #1170672 - Submitted on 12/15/14 by Callsign KA4NNN - IP: 173.209.212.209 Click Here to Email -- Click Here to View Picture -- Send this Ad to a Friend

I bought a Gates BC1 from an independent engineer...He delivered it to my shack....The transmitter was lying down on a boat trailer..all the tubes and iron still attached....We slid it off the trailer, stood it up and it fired  up on 1250 a couple days later...That was 15 yrs ago and those tubes are still in the transmitter...I don't recommend this method, but it goes to show what you can get away with....

Why?
The things are huge, old, dirty, and huge.
If you get one, you may have to figure out how to get rid of it at some point.
There are much easier ways to get an even better signal on the air these days I think, all in a package with resale value that only takes up a desk top of space.
And some of it will do all band, all mode, with a great RX built in.

It was a rage that was going on around the middle/late 90's to get a broadcast rig and convert to 160M. Our friends from the Left Coast started the craze of acquiring old B'cast TX's. Just before a Gaithersburg Fester a fellow from the West coast had heard that I had a BC1-H and wanted to see it in action. It was a neat surprise visit.
The dirty secret might be that folks like to run the full Kilowatt (NOT P.E.P.!!) and be the channel master. None of the consumer stuff available is going to give a Kilowatt out.
I kinda agree about why get one when they are so hard to transport and convert and power. And when the fun is over; how the heck do you get rid of such a large unit?
The "craze" part of the ownership was the audio. Nothing required to re-engineer a military unit or a hundred watt table top TX. It was move the beast, give it 220, and convert to the Ham bands and have some sort of nice audio equipment and mic. Some folks like to exercise the grey matter and get that old plate modulated beast to operate again and make that B'cast quality audio a reality.
The magic stuff of today is almost a no-brainer to get on the air and have DC to light audio.
And there are flippers around who may have been given a B'cast unit and want to sell it for $1200....No thanks....The Gates unit in eBay went exactly for what it was worth.
Fred

Build your own.  Same amount of time and work.  Which rig would YOU rather have?


http://www.ebay.com/itm/Gates-BC1G-1000-Watt-AM-Broadcast-Transmitter-/251736184499?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2047675.l2557&nma=true&si=zn6nHz2kCCegxy29X3cgjQaTLS4%253D&orig_cvip=true&rt=nc

OR:


http://amfone.net/Amforum/index.php?topic=36463

 ;)

T

Chuck did it again!!!

The Gates was once on eBay. I wonder what happened?
Fred

My take on it is to get the BC rig, strip most of it out, throw out the monster enclosure (unless you can re-use sheet metal or chassis sections...), repackage it into something that suits your stylistic and space requirements. Like atoms, that are made up mostly of empty space (allegedly) the BC xmitr is likewise...

                      _-_-

If I was young and had plenty of space (and no wife) some were very good looking, at least from the outside.
Its not very hard to brew up a KW amp, or maybe a class E rig.

The size and weight are really something to think about!

Possibly a novel approach to owning a B'cast TX. Re-packaging the awkward electronic assemblies would take some imagination. The "guts' were usually mounted vertically on a panel and the tube sockets likewise. So, there would have to be some backward thinking to accommodate a smaller box and not something 7 feet tall. There's no getting away from the weight of the iron.
I would think the layout of the electronics were for ease of maintenance and air flow. The entire concept was for 24/7 operation and reliability.
Fred

I am still waiting for a transmitter to pop up in Michigan or Ohio. Have truck will travel.

John N8QPC

Keep the Faith Detroit47, John
I will be waiting too but no have truck will travel.
I visited the two AMers in town and the engineers are Hams too and ALSO waiting for giveaway transmitters.

There's no right way to do it - you can build your own rig using broadcast parts, or restore the broadcast rig itself.  It is really a matter of taste and personal preference.  I love to homebrew stuff but I also enjoy restoration of commercial gear.  For legal limit AM I chose to restore an existing broadcast transmitter and convert it to ham band operation, rather than homebrew a complete new transmitter.   

I have two Gates BC-1T rigs - one on 160 meters and the other on 75m.  I liked the first well enough to  restore/convert a second rig (rather than to add bandswitching to the first one).

http://www.wd8das.net/gates.html

When building a homebrew high-power transmitter guys often use a standard 19" rack as the enclosure, and sometimes that's a bit tight for components of this size.  One ends up moving heavy chassis around.  I prefer the larger cabinets of the old broadcast rigs and work on them in place.  Plus the control system, power supplies, interlocks, etc are already done. 

Steve WD8DAS

My thoughts on owning and operating old broadcast transmitters:
Like everything in life, if you got to ask you probably won’t understand. Thirty or so years ago while I was still in high school and because I was a Ham I was able to get into broadcast engineering. The RCA and Gates stuff was still in use in many of the smaller AM broadcast stations and spent many hours cleaning, changing tubes and other operations trying to keep that stuff on air. At the time you regarded that stuff as junk and dreamed of the day that you would have an all solid state transmitter that did not require almost constant support, then years later when you find for the last ten years or so you have not seen or changed a tube and you live in a world where you almost never have to do anything with a transmitter except to change out some non-field repairable sub assembly you start to look back on that old junk with some sort of fondness and then you learn of transmitters that are being taken off line and destined for the scrap yard the idea creeps into your head about maybe bringing one home and converting it to 160 and maybe running it sometimes.
So that’s how I ended up with my RCA BTA1-MX on 1.885 and yes there is lots to be said for the idea of a nice new small transceiver and all its capabilities but I am one of those hams that have no burning desire to just get on the air and talk and am much more content to work on the stuff. And the old AM stuff has an advantage over all the other broadcast equipment that is being decommissioned now days with the older generation of tube FM broadcast transmitters and just about everything that was involved in analog television being all too high power, too large and now too obsolete to have any use or value so don’t expect to see any of that junk in ten or twenty years but the old AM transmitters still can have some limited use in the Ham bands, but it’s just to a select few.
So it’s like owning a vintage car, or an antique tractor, although a Gates BC-1 may not have the same appeal to the general public as a 47 Ford N at the end of the day if it appeals to you get it and if it don’t its only so much junk. Owning these large obsolete and often dangerous things may have its downside, but if it’s what you want to do then that’s all the justification you need.
Do have to wonder if the current generation of Harris DAX-5 and BE AM-6 transmitters will have any appeal to future Hams or if being all solid state and complex will be of little value when they get retired?

Sure, shoot me the old Harris stuff. Would love to get the finals out of a now obsolete solid state VHF NTSC transmitter! Got any? :D 

                                     

Sorry, everything I did was UHF channels 28, 44 and 56 can set you up with a 30 kW liquid cooled IOT though. It’s an old article in Current but still somewhat relevant being at all of the above stations all the old analog stuff is still there somewhat, in the case of channel 28 we moved the transmitters into the parking lot and over the last couple years we have been removing antennas from towers but still all that old analog junk is lurking around transmitter sites:

http://www.current.org/wp-content/themes/current/archive-site/dtv/dtv0904analog.shtml

Also have a sixteen bay Bogner channel 64 antenna lying on the ground that would make the world’s largest G4 antenna!

The mad rush to convert the AM's to AM-HD is dead in its tracks. So, the old analog TX's will be in service until there are no more watts to emit.
AM-HD is really amazing audio. Just like FM, and it travels much better than FM-HD. The multi-path driving in a city and buildings kills FM-HD.
The AM-HD was poorly conceived and caused a lot of interference at night. Most of those HD signals are off now. They shudda moved the AM's where the old analog TV was.
Fred

Once the FCC finishes sorting out comments from the recent AM revitalization NPRM, I believe we'll see them force AM to all-digital operation in the next few years. I don't see too many other ways for them to fix the present mess.

73,
Jim
WA2AJM/3

Our flagship station runs a B.E AM-6A transmitter.  I like it -very reliable and good performance - but it doesn't have the same romance as the tube rigs.  And for hobby purposes that romance is important. 

Plus there are frequency-determined parts on every module, greatly complicating a conversion to the ham bands.  I bought an AM-1A transmitter on eBay for a song in the hopes that it could be a second backup to the AM-6A.  Its control and driver boards are useful, but the RF/Mod module can't be used directly as it is set up in another part of the broadcast band. 

Steve WD8DAS

I parted out a LARCAN 44 kW channel 11 rig a few years ago. It had the 1980 MOSFETS in giant slide in heat-sunk plates, that could be swapped out. Lots of them. There may be one or two left, the rest were scrapped along with the cabinets and power supplies. All the coax combiners, splitters, phase shifters, diplexer, aural cavity, etc were kept, and reused at the particle factory for 200 MHz, very useful pieces. Lots of 3 inch and 1 5/8 inch rigid line too. 

Same thing can be said for the Omnitronix rigs, lots of trouble to move them up past top band. They built a tropical model, but I'm not sure how well it worked. I designed the PDM modulator for that line, under contract, in the 1980s.

More thoughts about tube broadcast transmitters and why anyone would value them.
I can’t imagine anyone running a tube transmitter in commercial service these days, least not at the one of five kW level. I had couple sites with old Harris MW-5 transmitters as primary and backup and the one thing you could count on was every year you had the change out the modulator tubes with the PA having to be replaced once every two years so after ten years you were looking at close to the replacement value for the solid state. Back around the late nineties and early part of two thousand both sites were converted over to DAX-5 transmitters and then all of a sudden no more tube changes! The only issue is the new Harris has no tuning or load controls and is designed for 50J0 and if you don’t have that bad things happen. On a sister station where one is installed they had to remove it and replace it with a BE AM-6 being that was capable of working into their flakey pattern. Looking at the revenue from our AM stations would think that if we had to purchase a new transmitter or go HD the company would just turn in the licenses. With automation and all solid state transmitters you can run an AM property for little more than the cost of utilities but unless you’re in a top market the land that your tower farm and transmitter site occupies is worth more than any revenue the station generates.
Just can’t see much love for the current generation of solid state transmitters and think when they go off line they will end up just being used for parts. Just don’t see someone getting a Harris DAX and modify it for Ham use. Maybe the old tube transmitters were something like the steam locomotives? Difficult to keep running, temperamental and labor intensive but just like steam they have a certain feel or romance about them so that’s why we save and occasionally use them where the solid state more along the line of a diesel and who cares about diesels?

The attraction to tube transmitters for the Ham community may be the last bit of nostalgia that is easily converted to the Ham bands without major brain pain. Today's solid state stuff is not so easy to move and that's the nature of the beast. The reliability of solid state has put a lot of engineers out of work.
So poo poo the tube transmitter and its need of TLC. That was the beauty of it. WABC, 770, probably had an engineer on duty 24 hrs a day to keep that ole G.E. humming. They brought a Harris MW-50 online and they said it never sounded like the G.E. plate modulated rig. Something about feeling the bass notes on the concrete floor from the modulation transformer. Some newer engineers do not like the beauty of tube equipment. Turn it on, look at the meters, and lock up the site.

An odd-ball transmitter that has tubes:
There was a Collins tube B'Cast TX (Collins 820D) typical Collins engineering, that was not so friendly to move. Mike Dorrough had a couple of articles in ER magazine describing the miseries of moving the TX to 160M.
Fred

The add now says a sale is pending.

Bill

Got my Collins 300G 8 miles from the shack.  Piece of cake to move (after we got it out of the transmitter room.)

That's awesome Dr. Roy! I wonder how many people who run converted broadcast transmitters might have actually listened too (regularly) the same transmitter when it was being used in a broadcast station.  That would be really cool to obtain a retired one from a previous favorite station.

The deadline of Jan 5 might be a show stopper.
Fred

Yes, it is true!
The same Gastes Beastly Sea One-Gee sold yet again on Epay. For $201 bux!

Almost bid on it myself, but lacking certain information or means of contact, I restrained myself.
A bargain to be sure.
Assuming you could go and get it.

Was going to pack my oxy-acetylene cutting rig and sawzall to reduce the weight of individual componenets,
and to speed load out. At least that was the thought coursing through my mind.

On another note, a fellow with a neat looking Racal receiver - looking like a 4" high R-390 - did NOT sell it for $449, so he just
relisted it. This time for $559. Yah, that works for me. How 'bout you?  :P

As hams age the want for a BC transmitter in the shack will INCREASE.
1) clean it with a hose rather than Q-tips. Poor eyssight really does not do well with Q-tips. Q-tips needed for ear wax.
2) no more lifting.  You stand and work in the transmitters rather than sit with them precariously balanced on a bench.
3) 160 meters - nobody's home. Plenty or room for those 16kc wide signals without an ssb net halfway across the country stirring the nest.
4) toobs - troubleshoot with and panel meters rather than tiny LCD newfangled chinese-made computer thingys.
5) warmth - when oil shoots up again in price you'll be glad you have auxiliary electric heat that doubles as a transmitter.
6) transport with a pickup truck requires you to have a pickup truck.  Everyone loves trucks.
7) can use as a boat - covered in earlier post.  Important as climate change raises sea levels.  Toolshed when not floating.
8) makes any mic sound good.
9) Woman aren't saying "it's so big!" to you?  They will after you move the transmitter into the living room.
10) Surely there are more good reasons.  I love my Collins 300G

It looks very comfey in the living room.

klc

Shiny too...

"...man's best friend..."??


The other angle I had on the Gates is that it looked like the cabinet, sans guts was perfectly suited for conversion.
Conversion to a very nice over and under refrigerator. Something any XYL would love to see everyday in the kitchen!

Look at it, perfect, just splice the front panels to the door skins of a properly selected and sized refrigerator!!

You're living the good life, bro.

Apparently it is back again, this time with an increase of $100 in the starting price.

As the now classic song says "...should I stay or should I go?..."

Don't the CBers know the 833's don't like 11 meters so much?  Or don't care.

pricing up.. a guy I know sells used tubes. He couldn't get $5 but when he started listing them for $25 he got people buying them. Apparently some people think that a low price always means junk. If the BC rig seller's hoping to price it up above CBers, he may have a shock, as they'll spend foolishly.

I have a van, so I got no problem getting something that size. Moved two BTA-250L's, those weigh 1300 lbs.

Socket set, wrenches, sawzall w/metal blades, ox-acetalyne cutting torch... moves easy! :D

I still favor the "refrigerator mod"...

                              _-_-

PS. if the outfit handling the sale had contacted me, it would have been picked up and moved a
few weeks ago...fyi, fwiw, and all that jolly good stuff.

Crap, I feel older now, that tube FM transmitters are being pulled out of service. I was designing SOTA tube FM rigs for BE from 1981-85 in Quincy, down the street from the Gates/Harris Tin Works. Damn silicon has taken them away.

I just sold off my BC-1H1 as I needed the space and it wasn't getting any attention since I got it, still on 1190. Hopefully it will pop on the air from upper Wisconsin sometime.

Hope you did not have anything to do with the FM-30 and that squirrely grid input tuning mess! Or the IPA system that used an entire rack full of junk to do what Harris did in one brick size amplifier?

Well, thanks for your comments! Did you have an FM30 or FM30A or FM30B? I was there when the first FM30s were going out the door. I had just joined the company. I changed out the stoplight controller 1 bit microprocessor controls to CMOS logic with a later Z80 add on for logging. The original grid circuit was quite narrowbanded, and it took a while for them to convert over to more broadbanded. I developed the FM3.5, FM5, and started on the 10 when I departed Quincy for the east coast. These had the first of the broadband input design, where we switched to a microstrip board to do most of the Z transformation, and only used the inductive slider to resonate the grid/cathode capacitance. At the time Harris had nothing of this sort. We are neck and neck competitors in the 1980s with them.

For the IPA, not sure about what you meant by a rack of junk? Was it a rack full? The first FM30s had CTC BM100-28 or something like that, aluminum metallization bipolars, 2 per board, and had 4 boards plus a driver, it was mounted horizontally on the lower front of the cabinet. It had a big 3 phase linear supply. It was an ugly and unreliable thing with mica trimmers all over the place. DMOS transistors were not yet available to do a broadband IPA, so my design started with the TRW TP9383 150 watt bipolar and later switched to the ST Thomson SD1460 BJT. A pair of either made a 250 watt semi-broadband amplifier (10 MHz max BW). It was a big blue drawer, with built in linear regulator and power transformer, 28 VDC. I know that they stacked those drawers for a while in their products. At the time, Harris didn't have a single brick IPA either. That took a while, and Bob Artigo, Bobby McDonald and others (ex CTC) developed a line of blue 700 watt modules that Harris, Continental both bought to use as IPAs. Harris may have then built their own at the time. BE later (after 1985) went to DMOS drivers, and I have no idea how that was packaged into their transmitters.

BE's claim to fame in FM was the half wave output circuit, that didn't have sliding contacts or a blocker capacitor. That was a piece of work, and we were very proud at the time. There were those who said the stored energy in a half wave resonator (high Q) would degrade the FM wideband signal, but I proved this wrong in experiments, both grounded grid and grounded cathode 4CX3500A, in a paper I wrote that later became part of the 7th edition NAB handbook FM chapter by Mendenhall.

I still use half wave circuits where I can, due to the simplicity of tuning with a bellows or cap at the end instead of a scraping finger contract on a wall.

The FM-30 I think is a 30B with the blue amplifiers and is located at WSCL in Seaford Delaware. Along with there now retired engineer Bruce have been working on that transmitter for all of the thirty years it has been installed when new. Not many parts that have not been replaced or issues it’s not had. Replaced the entire grid input tuning section for the PA about twenty years ago and have to give some credit being it has been in operation now continually for thirty years with no backup and limited regular maintenance. They are going to replace it soon and have recommended a Nautel but have to wonder what that would look like in thirty years.
Also have a FM-10 as a backup in another site but that’s the newer tan version that sounds like a water pump when the filaments come on.
Imagine the design of the PA cavity is why they never tune like any other transmitter; lack any type of plate dip or anything like that.

30 years on that rig is pretty good. The grid circuit has to be cleaned occasionally, esp the tuning sliders, as it is true for Continental, Harris, and the rest. Fine dust gets through whatever air filter there is, and settles there. I think the solid state rigs will be fine, but they too must be cleaned. At least they don't have the HV to attract dust and flash over.

FM10 sounds like it has a bad blower bearing if it sounds like a water pump! Have you tried a little oil at the motor, or are they sealed? I can't remember if the 10 had the cylindrical 'stovepipe' cavity circuit or the big box like the FM30?

As for plate dip, I think most of the cavity circuits like that didn't act like a typical 6146 and pi network. The plate dip is ever slight when loaded correctly, and it is more important to watch for peak screen current when tuning. If the efficiency is lousy, then adjust the loading and retune plate. We always used screen current peak. BTW, screen current on a tetrode in class C or B is very sensitive of loading as well as VSWR. Thats why the VSWR foldback circuit in the BE's worked to keep screen current from overloading when icing up happened on an antenna.