Just tho't I'd pass this along because of the resurgence of messages involving Part 15 AM Carrier Current operations:
http://k6prk.org/CARRIER%20CURRENT%20AM%20TRANSMITTER.HTM
Just tho't I'd pass this along because of the resurgence of messages involving Part 15 AM Carrier Current operations:
http://k6prk.org/CARRIER%20CURRENT%20AM%20TRANSMITTER.HTM
... So, since RFB has been contemplating a small CC unit design which wouldn't need a separate coupler, I tho't at least that portion of this circuit might fit since its coupler is built in .... it's designed to just plug into a wall outlet.
HTH ...
Dear Ken Norris:
You no sooner posted this fascinating link than I grabbed it and also linked it on my part 15 page on my site.
Thank you for another insight into the carrier current world.
that page has been there for ten years. i'd like someone to comment on how good or bad the design is.
"i'd like someone to comment on how good or bad the design is."
It's a good design that will get the job done. A limited range coupler meaning it will not have much isolation capability to the 60 cycle hum unless the output tank is re-designed using a ferrite core toroid, which would also give better coupling efficiency and wider tuning range and very little inductance reaction to the constantly changing inductance of the power lines..including the neutral that carries all the return currents.
Overall, a great starter and most certainly a design that can be a base for a larger and more refined unit.
In adding to the post, the coupler I have designed uses a ferrite core toroid with several tap points connected through a 10 position wafer switch for the "line side" tuning. It is built around a 75 ohm input loading impedance for the TX, mainly the TH or similar types, but I may put a second input load selector switch and wind the primary to allow for both a 50 ohm and 75 ohm input. As is it handles about 5 watts and can couple as little as 70mW.
RFB
i would be interested in the designs for a switchable (50/75 ohm) version. the power should be really upped to 20 watts pep most commercial CC TX's are 10 watts these days and the old lpb, cunningham, and Radio systems are 20, 30, and 50 watts adjustable.
I have considered a higher power version. This first unit is mainly for those who do not have a transmitter of 10 watts or more. Since most of the "do it yourself" projects in the library resources have transmitters of the 2 to 5 watt variant, and that this coupler was mostly intended for those with the Talking House or iAM transmitter or similar unit with an RF output connector sporting a standard loading impedance, this is why the first unit is for low power stuff.
For the higher power levels, I would go with the much larger couplers anyway. Although my coupler could be "beefed up" to handle 10 or 100 watts, that would take it beyond the scope of its intended purpose for the low power levels, not to mention it would be rather bulky and not fit too well onto the typical power socket without having to use a power cord.
But who knows...I might get bored enough and start winding toroid transformers and assembling something!
RFB