Does anyone know where i can find a schematic to biuld a transmitter for standard broadcast. There isn't much on AM where I live. Thanks,

I can get you some schematics, and you can also buy a kit from www.tubesandmore.com. All you really need to do is build an oscillator circuit like that found in most five tube AC-DC radios (or AC radios, but many circuit variations exist here). Use a common oscillator tube like 12SA7 or 6A7 or 6A8. You can use a combination of two tubes by using a triode for an oscillator and a pentode as a converter. You can either use an air tuned coil for the oscillator, with an accompanying condenser for finding the frequency you wish to use, or you can use a permeably tuned coil, which can simply be tuned with the slug inside the coil.

More elaborate versions may include strong RF amplifiers after the oscillator, which will increase signal coverage (which may or may not be illegal in your area, but as long as you don't interfere with anyone and cause complaints, you won't likely get in trouble if you only broadcast on occasion).

Thomas

I would be interested in get some schematics too, if I understand what JK wants is a small local transmitter for AM broadcast but not as little as the unit that sells Tubesandmore which is for indoor use mainly.
I guess he wants to transmit signals more far than the walls of his house, Ilegal or not.

Milton

:I can get you some schematics, and you can also buy a kit from www.tubesandmore.com. All you really need to do is build an oscillator circuit like that found in most five tube AC-DC radios (or AC radios, but many circuit variations exist here). Use a common oscillator tube like 12SA7 or 6A7 or 6A8. You can use a combination of two tubes by using a triode for an oscillator and a pentode as a converter. You can either use an air tuned coil for the oscillator, with an accompanying condenser for finding the frequency you wish to use, or you can use a permeably tuned coil, which can simply be tuned with the slug inside the coil.
:
:More elaborate versions may include strong RF amplifiers after the oscillator, which will increase signal coverage (which may or may not be illegal in your area, but as long as you don't interfere with anyone and cause complaints, you won't likely get in trouble if you only broadcast on occasion).
:
:Thomas

Hi

JK posted his question on another forum. He got some good leads for schematics.

http://antiqueradios.com/forums/Forum13/HTML/008098.html

Norm

:I would be interested in get some schematics too, if I understand what JK wants is a small local transmitter for AM broadcast but not as little as the unit that sells Tubesandmore which is for indoor use mainly.
:I guess he wants to transmit signals more far than the walls of his house, Ilegal or not.
:
:Milton
:
::I can get you some schematics, and you can also buy a kit from www.tubesandmore.com. All you really need to do is build an oscillator circuit like that found in most five tube AC-DC radios (or AC radios, but many circuit variations exist here). Use a common oscillator tube like 12SA7 or 6A7 or 6A8. You can use a combination of two tubes by using a triode for an oscillator and a pentode as a converter. You can either use an air tuned coil for the oscillator, with an accompanying condenser for finding the frequency you wish to use, or you can use a permeably tuned coil, which can simply be tuned with the slug inside the coil.
::
::More elaborate versions may include strong RF amplifiers after the oscillator, which will increase signal coverage (which may or may not be illegal in your area, but as long as you don't interfere with anyone and cause complaints, you won't likely get in trouble if you only broadcast on occasion).
::
::Thomas

Yeah, the leads I got from antique radios seem to be good, yet pretty simple schematics.

http://antiqueradios.com/forums/Forum13/HTML/008098.html

Here is the Schematic of the 6BM8, I thought about using a 6j5gt, and a 12V6GT instaed of the 6BM8. What will be performance changes other than output, i should have more output with the 12v6gt right? sound should still be pretty good? I might build a second one using a 6U8A for comparison.

http://www.oldradioz.com/schematics/AM_Transmitter_6BM8.pdf

Thanks for all the help. JK

Hi JK

Increasing supply voltage will give more output power. Should be able to get 5 watts with a 12V6 & 300 volts B+.

Norm

:
:Here is the Schematic of the 6BM8, I thought about using a 6j5gt, and a 12V6GT instaed of the 6BM8. What will be performance changes other than output, i should have more output with the 12v6gt right? sound should still be pretty good? I might build a second one using a 6U8A for comparison.
:
:http://www.oldradioz.com/schematics/AM_Transmitter_6BM8.pdf
:
:Thanks for all the help. JK

What about using a signal generator as a broadcaster? I tried it. Various sites regarding this on internet.

:Does anyone know where i can find a schematic to biuld a transmitter for standard broadcast. There isn't much on AM where I live. Thanks,

You can use your signal generator as a transmitter. It must have a modulation input (audio input). I have done it with mine. My generator isn't that strong, but it does the trick. If you want, just connect the generator directly to the antenna of your radio. This is somewhat simpler than going inside of the radio and connecting your CD player to the amplifier.

Thomas

I just draped the output wire from the generator over the top of the radio cabinet, and it worked good.

:You can use your signal generator as a transmitter. It must have a modulation input (audio input). I have done it with mine. My generator isn't that strong, but it does the trick. If you want, just connect the generator directly to the antenna of your radio. This is somewhat simpler than going inside of the radio and connecting your CD player to the amplifier.
:
:Thomas

A good bit of useful information has been given on this subject already, but for what it is worth, a modified version of the phono pickup transmitter that was used in the Zenith S7000 series radios can be used for this purpose. If the secondary of an old AM radio tuning coil is used with its original tuning condenser, it will tune the entire broadcast band. This is the circuit that Antique Electronic Supply (www.tubesandmore.com) modified for their kit. The schematic for the Zenith version is at:
http://www.nostalgiaair.org/Resources/657/M0025657.htm

This circuit uses a 12SA7, which was the tube mentioned in a recent post:
http://www.nostalgiaair.org/Forums/Messages/695/M0032695.htm

This project used a disguised 12SA7 and several vintage parts to build a transmitter to look like a home brew set of about 1924.

:Does anyone know where i can find a schematic to biuld a transmitter for standard broadcast. There isn't much on AM where I live. Thanks,

Yes, at least Frys used to sell a FM stereo kit for 40 dollars or so. I built one, and used it to listen to my CD changer in the house while I garden with a walkman, it works for about two houses, then fades out.

Hey Todd-
I have been trying to find you to let you know that I have mailed the transformer out that you purchased on Ebay. Ebay did indeed suspend my account. I have been selling on Ebay for just under a year and it has been continually jumping through hoops. I have perfect feedback and never an unhappy customer but they continue to give me headaches. Anyway so when you contact me by email I cannot respond b/c my account is not active. So I sent the transformer out yesterday, Saturday. It was sent Priority so you should receive it within a few days. I hope this reaches you before you stop payment on your money order. If you get this please give me a call.

Thanks,
Amanda Sharrai
734-260-0517 (cell)

:Does anyone know where i can find a schematic to biuld a transmitter for standard broadcast. There isn't much on AM where I live. Thanks,

I made a few http://home.comcast.net/~suptjud/AMtransmitter.htm

I think that eventually we all will need to purchase or build some sort of transmitter as there is less and less to listen to on AM anymore. What a pity. Where I live, we have one station that plays oldies and another that plays R&B. At night, I look forward to picking up Toronto on 740. That's a great station. Mark from Kalamazoo