Broadcast Transmitter

[AB3FL]

Where do all of you find these old broadcast transmitters to convert to HAM bands?


Tom - AB3FL

[W2XR]

Tom,

Try contacting the chief engineer at some of the small market AM stations in your area. If you are lucky, the old plate modulated rig in the transmitter building is still there and is no longer being used as an auxilliary/back-up rig. These transmitters are considered by the ever cost-conscious station management as being just too big, heavy, and costly to be removed from the facility.

Perhaps if you make the right pitch of offering a reasonable price to purchase and handle all of the details of removing the transmitter from the premises, and clearly indicate that you are a radio amateur and what the transmitter will be utilized for, the rig will be yours.

I have been pretty lucky along these lines, having acquired a Gates BC-1F and a BC-1J at no cost, and a Gates BC-1G for $400.00. All three transmitters (and particularly the BC-1F and the BC-1G) were in really excellent physical condition, were complete, and in ready-to-go/on-the-air condition. The BC-1F and the BC-1G had to be quickly removed from the stations where they were installed to make way for the newest generation of solid-state AM transmitting gear. The BC-1J was obsoleted/removed from active service when that station also installed the current generation of solid-state rigs for both the main and auxilliary transmitters, and that deal also included a brand-new original/never used/still on the factory pallet spare Gates/Basler 6200 VCT plate transformer. That transformer is doing service in my homebrew 2x 4-400A/2x 833A rig.

These old rigs are clearly out there. As with anything else, it just takes some persistence, good manners, and the willingness to go to the trouble of hauling this really heavy metal safely away. My guess is the more rural the station location, the greater the probability of finding the rig of your choice.

Good luck in this endeavor!

73,

Bruce

[K5UJ]

There are a couple of things you can do. 

1.  Dig around for web interfaced broadcast reflectors.  Broadcast techs use email lists just like hams.  In fact there is a bit of overlap since many of them are hams.  Here is one such site:  http://www.radiolists.net/
 Sometimes notice is given in these forums of AM rigs for the taking.  You may have to be willing to travel.

2.  Increasingly station maintenance is being outsourced to contract engineering firms.   Look around on the internet, yellow pages, see if your local library has reference sources that list broadcast industry businesses with addresses near your location and contact these outfits.  Ask them if they have any old gear they are getting rid of.  Don't necessarily limit yourself to rigs.  You may get old racks, mixer boards, phasors, you may have to take some junk you don't want to get the stuff that's good.   You will need a pickup truck, dolly, tools, and one or two guys to help you, preferably guys who know to keep their hands off the station equipment   

If you live in a small or medium town where the stations aren't all fortresses to keep the nuts out, you may be able to show up in person and actually talk to an engineer and get the local skinny on what's going on. 

I found it useful to subscribe to one or two broadcast tech email lists a few years ago to learn about AM broadcasting because I figured some of the knowledge would transfer to 160 meters.  After 2 or 3 years I figured I had learned all I was going to and dropped them but I recommend doing this because it will help you learn about the industry and what these guys are dealing with.  In with the stuff about antennas, feedlines, matching networks, mics, and such were a lot about tower lamping, studio to tx links, status monitors, call screening software FM and TV, and other production topics I had no use for, but the education was worth it.   You might get some contacts in your area too.

GL

Rob
K5UJ

[John K5PRO]

Yes, many stations have disgarded tube-based 1 kW rigs in favor of lower maintenance, higher efficiency & 'safer' solid state rigs. Those that are still running their tube rigs are either on a very tight budget, struggling to operate, or stalwarts that you shouldn't be bothering with anyhow. The majority have or are in the progress of scrapping the 833/4-400 tube-based radios at this time, and have been for past decade. Its up to hams to make contact with broadcasters. If you know where the local engineers hang out for lunch together, or have their local SBE (society of broadcast engineers) chapter meetings, you have an advantage. Start calling local class C licensed 1KW stations in your community, and ask for the chief engineer. Also, many broadcast engineers are also hams, so asking on the local nets and over-air discussions may lead you to your prize. Its really a word-of-mouth process. If willing to go beyond your region, then the approach of reading the online discussions works also. Bear in mind that these big iron units require shipping which isn't cheap, so if you must pay a lot for one you are already at a disadvantage. Also, that some of the older rigs may have had PCB-laden capacitors, which are no big deal to hams, as long as you don't discard of them in the landfill or in your yard. In this case, stations may be excited that you would take it away. Corporations like Clear Channel might have legal precedents that prevent them from scrapping out such equipment to individuals. That's why it's easier to deal with mom and pop stations.

[KX5JT]

I don't own a broadcast tranmitter... yet... but I do find this mailing list very enjoyable as someone who aspires to maybe own one one day...

http://groups.yahoo.com/group/bcast_xmtr_4ham/

Broadcast Xmtrs 4hams.... Mostly about restoring and using them on the ham bands.