[Milsurplus] Base Carrier Current ( Milsurplus Vol 132 issue 4 )

[Bob Camp]

Hi

The main problem with most carrier current installations is that in building power feeds 
are not designed as RF transmission lines. Toss in the stuff attached to them and the 
impedance drops even further. Net result is a transmitter load that is < 1 ohm for a run in a large building. 

If you start digging into these transmitters, the “interesting” part of them is the output matching
setup. it’s also the part most likely to get nuked by spikes and lightning. It’s the first
thing I’d check if I was buying one. 

Bob

> On Apr 10, 2015, at 5:54 PM, Hue Miller <kargo_cult at msn.com> wrote:
> 
> I would tend to agree that carrier current losses are so high thru transformers that
> multiple repeaters are required to cover a larger area.
> HOWEVER....
> I recall in Seattle, 1977, and I'm sure I have told this story before, but....when AM
> was disallowed at the end of 1976 for marine band comms, PNB auctioned off their
> 2522 kcs. transmitter of marine phone station KOW2. The young guys who bought
> this, around the same age as I, changed the freq to 880 kcs. and wired it for
> carrier current AND controlled carrier, so supposedly they could make legal
> measurement with no audio, and only no audio. They were located around
> somewhere like 90th St and 1st Ave North. I could hear them strong at 1.5 miles
> to my residence AND it did seem to DF to the local power line.  KLK 880 went
> on for several months until apparently they solicited advertisers, the potential
> advertisers raised questions, and the FCC got involved.
> 
> I recall Don Merz had a 50 watt AM broadcast transmitter setup for Army base
> broadcast station. This was intended as I recall, as a complete radio station,
> with turntable, and all. I really should have bought that, but maybe I wasn't
> earning as much then. I do have the manual for it somewhere.
> -Hue Miller 
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