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did they get the microwave dish and tower in that little box?
Neil
I had one of those Radio Shack AM radio station kits back in the 70's.
Seems the microphone circuit never worked and I made sure I had the transistors installed properly.
Anyone else experience that same issue with that kit?
Bruce.
HI Bruce: I did have one 28-209 back then and was on the air for 3 year with no issues even when i found snow on the unit it still ran like a timex watch.
Did you check your mike to see if it was good,There kind of cheap.
And on the 1 transistor in front closes to edge 2SB54 you had to bend the center leg backward if you didn't use a shrink tubing on that center leg you would have an easy short against the other 2 legs as well across the transistor body which would cause your issue.
I even found sometime if you did not have a good tight connection with them springs you would have an issue as well.
when i was on the air i did live shows and got about 3 miles out in some area only using a antenna with no ground and the antenna was up about 20 feet in the air.
The radio i used for picking the station up was a General Electric 3-5280B and the audio quality sound very good was on 1610 am.
as the kit goes i have 3 here it was my very first am station on the air and my fm was a mr. microphone.
The good old days. Station 8
How did you get out 3 miles with the kit? Did you have the antenna Outside? Was it a wire antenna made of speaker wire or copper wire? I bet if I were to get a 3.5 MM Stereo patch cord and take one end off and then split the two positive wires for right and left channel and then conect the copper ground to the ground connection I'd be able to get both stereo channels to play in the AM Mono mode. Might have been cool if I could still get ahold of one of those things. Only thing I bet the drifting was a horrible issue. Be cool if there was a way to end that. Then you'd have a cheap good sounding AM Transmitter you could connect to a mixer or even your computer.
Hi: Here was the set up that i can remember been a long time ago.
1) I lived in the country,1 mile outside town.
NOTE: Lived in valley but house was up on a good hill.
2) Transmitter was set up 50 feet away from house.
3) Tower support was made of 1x1x1 at 8 feet long 3 section, 24 feet total length.
4) Antenna was made out of 10 or 12 awg wire copper 6 inches straight section on top with a coil section about a 1 foot long and about 6 inches in width.
NOTE: It's been so long on antenna this is all i can remember and not sure if information is correct.
It was my first antenna design i tried to see how it would do and it did good in valley and up on hill area for what it was,But did have some dead spots.
The original wire antenna that came the kit didn't give you a good range so then i raised the transmitter with the wire antenna up higher and got a better range.
Then i said that won't work and put it up higher with a better antenna and saw bigger range.
station 8
I had transferred my kit to a circuit board I etched using the Radio Shack circuit board etching kit.
I do not have the kit anymore, but I still have two copies of the owners manual that came with the kit.
Those crystal type microphones were cheaply made, I had to connect a stereo to mono amplifier to the + and - inputs of the kit to get audio into it.
I know I had those two transistors oriented correctly, so I do not think it was that.
With the included antenna wire it didn't go very far, I used a 9 volt AC to DC adapter to keep mine going. That large coil on the plastic frame was kind of flimsy though.
I liked how the included paperwork explained how real AM radio stations operated compared to the kit version. I seem to have lost that paperwork though.
Bruce.
Hi Bruce:
I haven't etched in so long but i used radio shack stuff when i did.
As the manuals goes i have all the manual and the station write up paper as well.
I will be doing a special manual in pdf file with all it's information and even pictures.
I had to fix my mike when i got mine do to it would not work,If you notice on mike you could take apart do to it had tabs on the edges, a wire broke inside mine.
As the transistor went 2 went in normal 1 went in backwards, I did have a short on mine and found the front transistor leg did short against the body causing it not to have my audio at the time when i notice it i fixed and she worked with no issue after that.
As the original antenna, not a very good range, But make your own antenna and you will do better.
I also found do not run the transmitter in a house with alumium siding do to it has a very bad effect on it's range.
that's why i ran mine 50 feet away from the house and notice a big different in the range.
As the power supply went i changed the 100mfd 16vdc to 100mfd 35vdc.
Power supply i changed from 9 vdc to a 12vdc 500ma and notice range increase,But make sure the power supply very well regulated.
I have 3 good running units here and my old broken original unit.
I found a replacement transformer that someone use and you can get at mouser when i do the book it will have the information in that so if anyone wants to build one they can.
Just so you know i have been building manuals up so people can download you ask some guys like carl,bob,neil about what there like.
I was down do to no computer,But finally got back up to build manuals back up again,But taking a small break.
If you join the ALPB which is free that's where the manual site is at and would have excess.
This is some things i did with am transmitter.
Station 8
What would happen say if I were to run 100 feet of long copper wire as an antenna? I bet then I could have the transmitter in the house and the antenna running outside. It may go 3 miles on AM which would be very cool. Yes a Stereo amplifier would be really cheap or maybe just connect one of those Radio Shack mixing boards to it and then connect my computer to the mixer (which would give better audio in the first place as you can adjust the modularion on the mixer so as not to overdrive the transmitter). If I could only get someone to build this for me as I'm legally Blind it could be a nice cheap way to transmit though I don't like AM. What about instead of a VFO is there a way to modify the transmitter to be less drift prone? Maybe would have to go crystal controlled. Since you figured out a way to do this as a circuit board what would be really nice is to have the right project board or should I say case and then put the finished product inside a neat little metal case. Then I could put the transmitter on a desk and it would be made as well as a Sainsonic AX-05B FM Transmitter. Could do both AM and FM.
I do remember the Battery eliminator Radio shack made. You'd have to maybe put some sort of hum filter after the power supply. Then plug it in set the freq maybe to 1610 and have a ball. I know car Radio's could receive it pretty well around the area and it would slowly fade out to the 3 mile threshold. Hmmm even though I hate AM could be an idea to get AM back to music. Just don't kow how Progressive Rock would sound on AM? Would have to equalize the hell out of it to get it listenable in any case. But maybe easier than trying to run FM for the 1/4 mile I want to get.
It is not a very difficult circuit to transfer to a copper clad circuit board using that special ink pen, etching it and then drilling the holes for the parts placement afterwards.
I'll have to dig out the kit instruction manuals to see if I had inked in the circuit trace road map on one of them, I have those hidden away in my attic along with tons of back issues of Radio Shack catalogs and CB radio repair related photo facts and other CB radio related service manuals and modification manuals.
It's been a while since I looked at it, so I am not exactly sure what I did. It was either a circuit board road map or a detailed schematic diagram that allowed me a better idea of how to design the circuit board using a limited number of jumpers.
I'll dig it out later when I have time.
Bruce.
Hi Thelegacy: Answer to your questions.
Run 100 feet of copper wire would be a big NO NO by law for part 15 am transmitters.
Audio system I used radio shack mixer with amp to compressor/limiter then into transmitter. Note Would add another amp after compressor/limiter if i ran a long audio line to transmitter example 50 to 100 feet long.
As the transmitter shift of frequency i never had that issue with that transmitter it did very well for what it was.It cost me $7.95 back then.
Transmitter Range Would be determined by several things
Location, Height of Transmitter, Antenna being used, Ground being used or not.Noise in the area.
There are several transmitter out there that are good and have great improvment over some of the older transmitter.
Range You will get more and better range out of am then fm due to the law for part 15.
Here are some transmiters out there.
Procaster by chez radio - Very simple to set up and tune meter to full reading.
has built in compressor/limiter. Has good high and low without eq. Fcc certified.
Rangemaster 1000 - Need meter to tune up but can order with meter,Has power led setting on some units, when you have a green light your 100mw.Will need a compressor/limiter and will need a eq to balance your highs and low better. can conect several unit to each other to increase your coverage.Fcc certified.
SSTRAN 3000 & 5000 - These are kit form. Have compressor/limiter settings adjustments, Will need a meter to set your settings.Very good high and low balance without eq.
Grain Industries- Really don't know to much about but it is Fcc certified.
Talking house & I.am radio - Not bad unit, Has a automatic antenna turner , No compressor /limiter, Would need a eq for better high and lows,Fcc certified.
I own about 22 am transmitters and i like them all in there own ways.
Am stereo is very nice if you haven't heard it i think you would like check my section out.
Any more question feel free to ask.
Station 8
See why Radioshack was so good back in the day......they had all these things in a retail store that you wouldn't get anywhere else. To bad they're gone.
To Thelegacy, too bad you aren't in Canada where the rules are a little bit less strict...there's no 3 meter rule here, you could have any antenna length you want.
Mark
To Thelegacy, too bad you aren't in Canada where the rules are a little bit less strict...there's no 3 meter rule here, you could have any antenna length you want.
I looked at the I AM transmitter. Looks nice and it has a built in antenna tuner and is Digital and could sit on my desk and I could plug my 3.5 MM patch cord into my computer and then connect a piece of wire to it as an antenna and let it run outside. It says 3,000 feet with the built in or should I say wire that comes with it. That would be a little more than a quarter mile which would be good. But I can't see paying $300 for an AM transmitter because hardly anyone listens to AM. I'd pay no more than $20-40 for an AM Transmitter $50 would be really pushing it. If I had a guarantee I'd reach a quarter mile and I could just run a piece of wire or a indoor AM antenna I'd probably think about it. But AM is just not worth investing my rent money into when I have a fixed income. Now back when I could buy a 7K stereo and not bat an eyelash yes I'd have one and set it up and tell the neighbors about it. Probably run it on 1610 and try and get the AM Stereo mod for it. But never will I spend $300 for anything mono no way.
I believe Mark is referring to the BETS rules for broadcasting, where the AM restriction is field strength only (250uv/m at 30 meters). Such a field strength is barely above noise levels and pretty useless.
RSS210 is basically the same as Part 15, and antennas + ground wire + feedline are restricted to 3 meters. But you're not supposed to use RSS210 for broadcasting (however, nowhere is broadcasting defined).
The manufacturers and most micro broadcasters ignore the distinction and use transmitters that are RSS210 certified anyway, such as the ProCaster. I have yet to hear of anyone cited for broadcasting on the AM band with an RSS210 certified transmitter. Even on the FM band, Industry Canada tends to only go after the more powerful pirate stations and ignore the little guys.