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THE AM BULLETIN BOARD => QSO => Topic started by: 4cx250 on October 15, 2010, 10:36:14 AM

Title: What sould I do?
Post by: 4cx250 on October 15, 2010, 10:36:14 AM
Hello All!

     I recently received a call from a gent that wanted to know who was owner of a broadcast TX that I had purchased about 10 years ago. I think that they got my number from the station. It was a Gates BC 1-T.

     I told him that I still owned it, that I brought it home, hooked it up, and got it "loaded up" on the broadcast frq to the internal "dummy load." I told him that I never did anything else.

     He asked me if I was willing to convert it to a shortwave frq (don't know the frq,) and donate the TX. He then asked me If I would be willing to ship the TX, and travel to the country and set up the TX.

     He said that it would be 100% tax deductible, as they were a church org.

     I told him that I would like to help, but that I was now unemployed, and had trouble with keeping food on the table.

     He was very polite, and said that he would get back to me.

     I would like to help, but he is asking alot!

     Has anyone else got a call like this? Is this a scam?

     WHAT SHOULD I DO??????????


Title: Re: What sould I do?
Post by: W1IA on October 15, 2010, 10:41:16 AM
You can't be serious?

Title: Re: What sould I do?
Post by: KF1Z on October 15, 2010, 10:59:13 AM
Depends on how bad you want to "help"

You're talking about thousands of dollars. (probably tens of thousands)
And probably a big headache.

Likely you will NOT get a tax writeoff for a charitable donation, as the organization is out of the country.

don't see it being a "scam" ,
They are already asking you to give away your time, your money and the TX.

Title: Re: What sould I do?
Post by: WQ9E on October 15, 2010, 11:07:53 AM
A tax write-off doesn't help if you are un/under employed and don't have a tax obligation.  Rules changes over 20 years ago greatly decreased your ability to income average over years; it was changed just before I was able to take advantage of back averaging in my transition from doctoral student to employed professor.

There are a lot of various religious organizations looking for funding.  A few are outright frauds but many more have good intentions but little/no positive impact.  There are a very small number actually doing a lot of good and they generally aren't the ones aggressively trying to put a hand in your pocket.  Furthermore, the airwaves are already crowded with various oddball kooks, fanatics, and other misguided individuals spouting forth their own particular brand of lunacy and contributing your transmitter will likely do nothing to save souls, improve the world in general, or anything else positive.  Sorry to be so cynical.

I would simply tell them that at this point in your life you are sorry but that you are unable to assist them at this time.

Title: Re: What sould I do?
Post by: K6IC on October 15, 2010, 11:44:51 AM
Completely agree with the above,

AND,  there are several pratical issues.   Bet the BC-1T runs 833s.    That rig and those tubes will probably not play well much above 5 Mhz without a lotta work.  And perhaps it would not have the Type Acceptance (or whatever) that the FCC might want to see ... and so on.

Think that iit is just fine to say "NO",  and feel fine about it.
Good Luck,   Vic

Title: Re: What sould I do?
Post by: 4cx250 on October 15, 2010, 11:58:23 AM
Hello All,

     I agree, I don't think that this call was a scam, BUT I think that the guy had a lot of balls to ask for what he asked for!

     It just seems to me that everytime that you turn around, someone wants something, or is trying to sell you something.

     I guess, WELLCOME to this world!


Title: Re: What sould I do?
Post by: KM1H on October 15, 2010, 12:11:15 PM
Begging and brass balls go together with those missionary groups. Jeez, the airwaves have enough of them already.

Title: Re: What sould I do?
Post by: K5UJ on October 15, 2010, 12:16:01 PM
I would think they'd want more than 1 KW for a sw bc station but I guess it depends on what freq. they want to use and how much terretory they want to cover.  Maybe it's a pirate operation (just kidding).

Title: Re: What sould I do?
Post by: KB2WIG on October 15, 2010, 01:14:29 PM
 " Begging and brass balls go together with those missionary groups "

Well, its kinda like asking girls for something. You just have to ask a lot 'o them. Sooner or later someone will say yes.


Title: Re: What sould I do?
Post by: WA3VJB on October 15, 2010, 01:27:30 PM
Having been involved in the "rescue" and placement of a couple dozen BC transmitters over the years, I really like to see these rigs STAY among us, and not go back into commercial service.

I had a guy pester me for several years about a 1973 RCA BTA-1S that I helped rescue from a station in Baltimore.  Turns out he had what he felt was the perfect use for it in Latin America where it would be on the air with a charity or religious group, and physically small enough to be taken there.  

It wasn't available anymore regardless, but after persistent questioning I said look --  I spend my time retrieving these things because the value of the transmitter and its components is far higher for those of us in the AM Community.  

In your case, even though you've never done much with it, you have a chance to pass it along among us to someone with the time to put it on the air with us and enjoy using it.

Do you think there's much technical support for a 50 year old transmitter in whatever country it would go ?  Cuba, maybe, where they do that with old cars because it's been hard to bring in replacements.

But I suspect whatever group this is would use it until the first crap-out, and it (and all your work) would be discarded.

Title: Re: What sould I do?
Post by: WD8BIL on October 15, 2010, 02:56:14 PM
Having been involved myself in out of country missionary radio work I'll put my 5 cents worth in.

If he calls back do what WQ9E suggested.
I would simply tell them that at this point in your life you are sorry but that you are unable to assist them at this time.

There are a number of good missionary organizations already setup to help establish new stations throughout the world. AND, if this application is in the tropics they'll wanna go solid state anyway. Vaccum tubes and high voltages don't do well for long in those settings. Everytime it craps out they'd be calling you to go fix it, again. So, if you're not ready for a long term commitment to this project, just say no.

Title: Re: What sould I do?
Post by: WA1GFZ on October 15, 2010, 02:59:31 PM
I remember the call I got from a guy who blew up Gary's 4-400 rig he sold to some tribe. They wanted me to perform magic over the phone on a blasted audio driver.
They will make you crazy if there is any issue.
Lose-Lose for a free after you invest a ton of time. 833As at short wave I wouldn't.

Title: Re: What sould I do?
Post by: K5WLF on October 15, 2010, 03:56:19 PM
If you're looking for a good home for the transmitter, I just love 833s  ;D ;D ;D


Title: Re: What sould I do?
Post by: k4kyv on October 15, 2010, 04:03:53 PM
833As are rated up beyond 30 mc/s, so I  don't think that would be a problem if the rest of the rf circuitry is designed right. The FCC wouldn't license a 1 kw station for shortwave, so it must be for some place outside US jurisdiction and therefore type acceptance wouldn't be an issue.

But for the reasons stated above and more, I think the transmitter would better be kept in N. America for use on 160 or maybe 80m.

If I had an extra transmitter, and some outfit like that offered to pay my travelling and living expenses and would cover the expense of shipping the transmitter, I might take them up on it for some exotic place like Tahiti (dream on), but sounds like these people want to have their cake and eat it too.

Wonder if the station they are planning to build is to be located in Nigeria?  ::)

Title: Re: What sould I do?
Post by: WA1GFZ on October 15, 2010, 05:06:38 PM
You are not going to get a HF layout in a MW rig.

Title: Re: What sould I do?
Post by: Bill, KD0HG on October 15, 2010, 08:57:35 PM
833As are rated up beyond 30 mc/s, so I  don't think that would be a problem if the rest of the rf circuitry is designed right.

Heck, Don, the RF layout in the BC-1s is lucky to even work at "VHF" on 1700 KHz.

Yes, you prolly could run an 833 or 304 on 10 meters, but it would take real plate neutralization and push-pull finals, neither of which are in the BC-1 series., which has paralleled 833s and feet of RF cabling on the RF side.

Title: Re: What sould I do?
Post by: Opcom on October 16, 2010, 12:33:45 PM
There ought to be enough TX's still coming out backup positions of stations for these sort of guys to find one for free and there ought to be, in their ranks of devotees, someone who can fix it. Several years ago I had basically the same situation but an 8KW diesel generator trailer I put on craiglist for $2000. Pestered me to no end until I was forced to be rude.

Here's a couple of questions for the BC engineers that have a bearing on this topic:

1.) As the 'backup TX's to be retired' become more and more solid state, will they, like the old tube ones, lose monetary value to the point they will still be cheap or free for hams?

2.) A customer called me about a 1KW SS BC rig that used one brick-style FET in the final. It was not an RF FET, it was a switching one and no longer made. They had gone through many substitutes and kept blowing up devices, whether in seconds or after 30 minutes. When the 15 year old BC rig blows up the MOSFETS in the final, and they are no longer made, what kind of hackery is needed to fix that?

Title: Re: What sould I do?
Post by: k4kyv on October 16, 2010, 01:35:16 PM
Like just about any used solid state device, the proprietary components are likely to be "discontinued" by the time the thing is released as surplus and any attempt is made to convert or repair the unit.

Regarding rigs like the BC1-T or BTA1-R, I wouldn't even think of trying to convert one to HF, although some hams have successfully made BC1 series transmitters work on 80m. The 2 1/2 ft. wire leads between components in the RF section would make a nice rf choke on the higher HF  frequencies, and can cause squirrelly operation even on 80m.  I never cared for the single ended, parallel tube, grid neutralised configuration, but I was surprised at how well it worked in mine after I converted it to 160m.  The neutralisation setting holds perfectly from one end of the band to the other, although it is never absolutely 100% complete at any frequency, even at the low end of the broadcast band, due to inherent deficiencies of grid neutralisation.

If I wanted to make a multi-band rig out of it, I would convert the final to push-pull, link coupled, with cross neutralisation, complete with split stator bread slicers for tuning capacitors.

The BTA1-R would be easier to convert while retaining the single ended final, since the finals are tetrodes, but the final would still require a complete redesign and rebuild due to the poorly designed phylical layout.

I believe the Collins 20V might be the easiest to convert due to its modular construction.  Simply build homebrew RF modules from scratch, designed for the desired frequency range.

The most hilarious thing I found in my BC1-T while converting it was how they got the rf output from the crystal oscillator module to the grids of the 807s.  No coax or even shielded wire.  They simply ran a wire lead, bundled into the wiring harness, between the two stages along with the filament and DC wiring.  That caused all kinds of squirrelly behaviour when I first fired it up.  I replaced the wire lead with a piece of properly grounded coax and that cleared up the problem, and I  got more grid drive to boot.

I replaced the stock grid coil made of Litz wire, wound on a bakelite form, with a piece of air core coil stock and that gave me another 25-30% increase in grid drive.  I  was able to get much better stability by replacing the 2 1/2 ft. wire leads with some 1/2" flat copper stock I had on hand.  Also, they grounded everything to the closest convenient point throughout the rf section.  I re-routed the wiring and as much as possible, grounded everything to a single grounding terminal on the chassis/frame.

Still, I have to carefully dip the 807 driver stage when tuning up.  If the stage is even slightly out of dip, I still get  plenty of grid drive, but the output from the final goes way down and the tubes turn red.  I suspect something is flipping into a parasitic mode.  One of these  days I plan to check out the waveform of the signal feeding the 833A grids hopefully to get a better idea of what is going on.
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