• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

KGO's signal

boiseengineer said:
A number of stations had (and still have) transmitters that could exceed their "rated" or licnesed power and were accepted by the FCC. The RCA KFXD 580 had would easily make 8-9 kw. It was a 10 kw with the second PA tube "removed". Many of the home brew or composite 50 KW transmitters were over built and could crank out a lot of power without much effort.
Click to expand...

But no modification (such as using a 10 kw modified for a 5 kw directional AM with power loss in the phasor) would never permit a 50 kw rig to run 135 kw. Maybe even 60 kw, as most transmitters had enough margin to be able to compensate for phasor loss... but I doubt even a 100 kw transmitter could make 135 kw.

Many of us, when 125% positive modulation was permitted, either put in power supplies from the next highest power transmitter, or got a modification accepted. I think in the case of KOMA what really was happening is that engineers were talking about the equivalent power in the main night lobe, which was and is about 135 kw.
 
JR1967 said:
I could already see the effect of the nighttime signals of clear channel stations being altered at night when I moved to Southern California back in 1993, and found out quickly that I could no longer receive stations like 700 WLW and 1120 KMOX in St. Louis, unlike back in 1986 when I was easily able to pick up both of these stations at nighttime down near San Diego.
Click to expand...
I know around 1990 the FCC mandated these "brick wall" low pass filters in front of the transmitter to eliminate monkey chatter. Does anyone know if this decreased the ability to pick up distant stations?
 
vibe said:
Another thanks, David, for your explanation to my question. had no idea that signals from San Fran and Schened, NY on 810 could possibly conflict. I thought the stronger one would simply win out.
Click to expand...

You're thinking FM. FM stations have "capture effect" where the stronger signal normally captures the receiver and the weaker one isn't heard. AM stations don't have such an effect. Even a weak AM signal can make a stronger AM signal unlistenable.
 
RE: KOMA

One vivid memory of mine is being able to pick up KOMA in Los Angeles and San Diego at night (in 1963). That's a fact.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom