I'm sorry to hear you are having problems with that
transmitter.
When I was young... (It was more important -
paying more paper, laughin much louder, yeah...)
Er um... I had been told that some AM BCB stations did use
LPB transmitters for low power at night. But since
those transmitters are all getting old - if they are
still doing it - any stations would probably be using
the transmitters from Radio Systems, I guess.
I'm pretty sure we had a 1000 watt daytimer that was
2.5 watts presunrise authorization. Years ago. Using
an LPB rig was easier than rigging up some resistors
hanging off of a tap from a big resistive load, or
whatever it is that they did (or do now.)
Trivia dept: As far as I can tell, there are 3 AM BCB stations
in the U.S. that run 1 watt power at night. I wonder
what THEY do?
I had that list somewhere...
Gee Carl, I hope you can figure it out.
Bruce, DOGRADIO
WDGR on 1210 kHz in Georgia was
1 watt and about 20 kW day, I think.
Actually, all I remember is the night
power being 1 watt.
This station has gone dark.
(I might have posted this before.)
Hey, Carl, maybe you can pick up
their transmitter!
Bruce, DOGRADIO
1 watt night - 1000 day - 500 critical hours.
Bruce, DOGRADIO
In Carl's peculiar mind the 1 Watt at night would be a lot more fun than the 20kW day.
I will try to track somebody down to grab that LP transmitter.
Full credit goes to Bruce, DOGRADIO.
EDIT FUNCTION ENABLED CARL HAS MORE TO ADD:
I went to radio-locator(dot) and learned a bunch of stuff.
Yes, the station had a CP to add nighttime service to a previously daytime license, at 1 Full Watt.
Station status: not currently on the air, like Bruce said.
The owner is Hye Cha Kim.
Original city of license is Dahlonega, Georgia, but the CP would make the new city of license Lawrenceville, Georgia.
What I might do, unless I don't, is contact him and ask about his plans.
If you could do that for me it would help a great deal.
The station's phone number is 706-864-4477.
Here's another oddity:
WNZK, Detroit
690 kHz - 680 kHz night!
The last station of it's kind in the U.S.
(I heard there used to be a Canadian AM
station that went from 710 to 730 night -
or maybe it was the other way "round.)
Anyway, this WNZK is 2500 watts day and
night, 6 towers.
Bruce, DOGRADIO
I love those oddities, Bruce, let us know every one you find.
In the early days here in Louis, Missouri (he's been de-canonized), some early stations shared frequencies.
The Post Dispatch had a station and the Lutheran Church had a station, and at a certain time every day they took turns using the same frequency.
HEY, at the end of the week the LPB carrier current transmitter is still over on the table waiting for me to take it apart and order parts, but I find plenty of reasons to avoid doing it.
This week two other Carrier Current threads opened up, with some very interesting discussion, which leads to me now having this book open and a new project in mind.
The book is The Encyclopedia of Electronic Circuits, and it has several schematics for long wave carrier current devices to use for various purposes. Reminds me of our other unfinished project, the Deep Voice Long Wave 1-Watter being designed by the committee that made the shortwave Big Talker. What about making the Deep Voice capable of operating in a carrier current mode down on 170kHz?
Spend the weekend thinking about it and let me know next week.
In thinking about finding a back-up carrier current transmitter I figured that the transmitter sold by ISS (Information Station Specialists), the T.I.S. company, would be suitable for CC, so I looked it up.
It is none other than the TR6000, same transmitter as Radio Systems, same uber price.
Say goodnight, Carl.
This is one long thread!
Life was good for awhile with the carrier current system built during this thread, but the LPB2-20 Transmitter broke and has been awaiting repair.
An LPB AM5 has been acquired but needs to have a new output section built for the mid-band, where AM 970 is our frequency of choice.
Meanwhile, AM 590 is open right now, as the licensed station on that channel has turned itself off for lack of revenue, and it may not be desirable for a buyer because the towers are 40-miles from the city in a farm field only 1kW aimed directionally toward St. Louis. Big expense, flimsy signal.
590 was the carrier current channel for St. Louis University in the 50s.
Now it could be mine, but these LPB transmitters, besides being old and prone to breakdown, need to be especially rebuilt for low, mid or high-band AM operation.
What I need is a new transmitter capable of 590 and 970 operation without major surgery, but the marketplace is dry.
Radio Systems appears to offer the ONLY carrier current transmitter -- at a stunningly high price -- and it's only 10Watts (max).
Although 5 - 7 Watts is acceptable for 970, back when my LPB was tuned for low band it needed more than 10Watts to feed the wires at 570kHz, where I ran tests.
Crazy thing is that so many AM stations now have extra-low-power night time authorization, from 1Watt up to 60Watts and such; where the blazes do they get their transmitters?
I scrolled around and found the major transmitter manufacturers tend not to offer anything lower than 500Watts.
Only the ALPB can save us in this dark time.
i traded for that greek 0-20w rms 80w pep am medium wave transmitter listed in the classifieds section. you may try looking on ebay for them they are only 600.00 new either plus shipping for free shipping i forget which but it seems to be decent for the price. be sure to specify balanced inputs if you want them though as unbalanced is the stock.
Thank you Robert and John...
I looked on ebay for that Greek transmitter, and it's not there right now, but it'll be on again. Maybe that would be a good solution for CC.
And the guide to RMS Power is worth a weekend of study, I mean, who does understand it... well, there's you John, certainly Rich and MRAM and Radio8Z, oh and Tim in Bovey... RMS power is everyday stuff for you guys.
"Root-mean-squared" is daunting for a guy who read Mad Magazine during math class.
How about the average voltage is 1/(t2-t1) times the integral from t1 to t2 of the voltage dt.
And the RMS voltage is the square root of (1/(t2-t1) times the integral from t1 to t2 of v^2 dt).
Math can be your friend.
Also note that the average voltage of a sine wave over many cycles is ZERO but don't be fooled into touching the wires.
Neil
@Carl
here is one. this is what i have....