PW AM Broadcast Transmitter Kit

[W1RKW]

https://www.amazon.com/Medium-Transmitter-Adjustable-530%E2%80%911600KHZ-Experiment/dp/B0CKZCK8P1/

Anyone that is interested in a PW rig for transmitting audio to any of their old AM BCB radios, this kit works quite well. It's not Part 15 compliant but can be made so if one wishes not to use it outside of amateur bands.  Just a 50ohm resistor on the output with a 4ft piece of wire can get you clean audio within a 100ft of it.

For amateur radio purposes, it can be tweaked to work at 160m. Ditch the VFO and inject a frequency of choice and it can be made to work 75m and up.  The carrier output power is greater than 1 watt however the audio level restricts you to dial back the carrier to about 200mW for a nice clean envelope. Audio frequency response is very good, almost flat actually.

I've been running it on and off for a few days now listening to my choice of music on some of my old buzzard AM BCB radios. 

The kit can be acquired already assemble via Amazon or  Ebay or unassembled via Aliexpress.  Aliexpress is less than $10 including shipping.

I'll post a schematic if anyone is interested.

[Steve - K4HX]

Nice find.

[W3SLK]

Didn't Ramsey get 'whacked' by the FCC for one of these units or was it their FM kit? I know Ron, WA3WBC had one going I think it put out close to a watt at the antenna, probably less radiated. Anyway, he had it linked to his 200 CD player that was loaded with blue grass and polka music. While he was out running errands he always had it dialed in.

[W1ITT]

I think  it was Ramsey that got gigged for selling FM transmitters that weren't type accepted in the Broadcast rules, Part 73.  Years ago I worked for one of the FM antenna manufacturers and we used to occasionally get photos of our antennas or clones of them being used in unlicensed FM situations.  Some were on top of apartment buildings and a few were just a single bay sticking out a window.  The Commission would usually send a couple fellows out to explain things and tell them to stop but many just moved down the street to someone else's place and kept on going until the stuff got confiscated after subsequent visits.  It seems like the Miami area was ripe for that activity for some reason.
Now you can get a cheap exciter on Aliexpress and a 100 watt LDMOS amplifier for not much money.  Plug and play antennas are not common but almost anyone can figure out a dipole or ground plane.
About 60 years ago I had an AM transmitter that was potted in black plastic, not much bigger than an ice cube.  It ran on a 9 volt battery, had an input for a crystal microphone and an antenna terminal.  There was a screw that ran a slug through a coil to tune up or down the band.  Not much new under the sun and it's all good fun.
73 de Norm W1ITT

[KD6VXI]

Norm

Back in the early 90s I worked on a Suburban for a pirate that had been busted a couple times in the Miami area.  Cuban guy.

He ended up going mobile at 2.5kw FM Stereo.

I moved a few months after it was all running, never did hear if he got caught.  I know he cloned the amplifier for a friend of his after I moved. 

Had the capability to run off the 454 with an Electrodyne alternator or he had a big penny that hooked up to a flat rack that hung off the trailer hitch.

Back in the early 90s all of southern Floriduh was a pirates heaven.

That was my first vhf amp, too!

--Shane
WP2ASS/ ex KD6VXI

[W1DAN]

Hi Bob:

Yes please link a schematic.

Thanks,
Dan

[W1RKW]

Here you go, Dan.

Some purchasing info:
Ebay has this already assembled. Price ranges from $28 to $50 depending on the seller and seller location. Lower end cost ships from China. Anything in the $33 to $50 range ships from the US.
AliExpress offers this fully disassembled for $14 plus $11 shipping and handling.
Amazon has it as well but costs a tiny bit more.
I purchased my assembled kit from Ebay for $33 and it shipped from NYC. Had it in about a week.

[W1RKW]

Sam/N8VES posted an online review of this and I was able to get in contact with him.  He sent me this nicely detailed assembly and test manual he wrote.  It also includes some mods/upgrades  along with some oscilloscope screen shots.