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Houston FM-SCA bandscan

M

Mediafrog+

A while back a poster wondered what was going on these days with SCA subcarriers on Houston FM's, so I finally got around to firing up my old SCA demodulator and checking what was on.

I only heard three stations with audio programming on their 67kHz SCA's:

KUHF 88.7--Reading Service for the Blind (this has been around for decades)

KPFT 90.1--Radio Maria (Spanish language Catholic programming; what I heard was locally produced)

KKHH 95.7--Vietnamese (or possibly a similar Southeast Asian language, but I'm 95% sure it was Vietnamese.) Locally produced, many mentions of local addresses.

No other audio heard on any other stations. A number of stations seemed to have idle data streams (transmitter readings?) and KHCB sounded like it had a high speed datastream.

There used to be quite a few more SCA's here: KODA had Muzak's easy listening for years, and the old KQUE had a Muzak competitor (name escapes me) with virtually the same type of music. I've heard various Asian language programming in the past on 101.1, 102.1, and 92.1. 97.9 once had the "Physicians Radio Network." And KHCB used to use their subcarrier as an (apparent) STL for 1400 AM.

Satellite delivery pretty much killed off music on SCA, and the various ethnic broadcasters have moved to the glut of brokered time AM's. I was surprised to find the Vietnamese on 95.7.

I don't have a demodulator for the 92kHz subcarrier, so can't speak to what, if anything, is on there.

Would be interested if anyone had more info on anything that I have missed.
 
.......and the old KQUE had a Muzak competitor (name escapes me) with virtually the same type of music.
The name was "Music-King." It was in the back of the KNUZ/KQUE building at 4701 Caroline @ Blodgett.
 
Not to be confused with, "Okay, but what does any of that have to do with radio?

It IS a part of radio. That's why the thread title is "Houston FM-SCA bandscan." Subcarriers to the FM were prolific in the 1960s and 1970s. It is a part of Houston radio history. Therefore, the topic is correct.
 
On a side note, sometimes when I'm driving without an SUVload of giggling teenagers, I tune to the Vietnamese station to provide syllables without meaning for me because it's kind of soothing. It messes everything up when my mind starts picking out the street names and proper nouns, because then the verbs all start falling into place. Does that suck as much for anyone else?

Just kidding, geek humor.
 
Forgive my ignorance here, but where could one get a tunable SCA receiver? We have some fixed ones we use at the cluster I work at that we use as emergency STL's. Sounds lousy, but it works. Also, is there another subcarrier frequency besides the 67 and 92? Thanks.


1
Mediafrog+ said:
A while back a poster wondered what was going on these days with SCA subcarriers on Houston FM's, so I finally got around to firing up my old SCA demodulator and checking what was on.

I only heard three stations with audio programming on their 67kHz SCA's:

KUHF 88.7--Reading Service for the Blind (this has been around for decades)

KPFT 90.1--Radio Maria (Spanish language Catholic programming; what I heard was locally produced)

KKHH 95.7--Vietnamese (or possibly a similar Southeast Asian language, but I'm 95% sure it was Vietnamese.) Locally produced, many mentions of local addresses.

No other audio heard on any other stations. A number of stations seemed to have idle data streams (transmitter readings?) and KHCB sounded like it had a high speed datastream.

There used to be quite a few more SCA's here: KODA had Muzak's easy listening for years, and the old KQUE had a Muzak competitor (name escapes me) with virtually the same type of music. I've heard various Asian language programming in the past on 101.1, 102.1, and 92.1. 97.9 once had the "Physicians Radio Network." And KHCB used to use their subcarrier as an (apparent) STL for 1400 AM.

Satellite delivery pretty much killed off music on SCA, and the various ethnic broadcasters have moved to the glut of brokered time AM's. I was surprised to find the Vietnamese on 95.7.

I don't have a demodulator for the 92kHz subcarrier, so can't speak to what, if anything, is on there.

Would be interested if anyone had more info on anything that I have missed.
Click to expand...
 
NHRadio said:
Also, is there another subcarrier frequency besides the 67 and 92? Thanks.
Click to expand...

I seem to recall another, 57 I believe, that some stations used at one time. I even heard of a case where a station had four of them in operation, but I think that was an experimental situation. You'd probably get a lot of good info about SCA's (certainly more than I could give you) by posing the question over on the Engineering board.
 
NHRadio said:
Forgive my ignorance here, but where could one get a tunable SCA receiver? We have some fixed ones we use at the cluster I work at that we use as emergency STL's.
Click to expand...

I got my demodulator years ago from Bruce Elving's FM Atlas business out of Duluth. He publishes the FM Atlas station guide, offers SCA demodulators that can be wired into FM radios, and also modifies FM portables to add SCA.

Site: http://members.aol.com/fmatlas/home.html

I don't think Bruce is as active as he used to be (age and health issues from what I understand) so I'm not sure if his business is still going at full steam. He has been one of the biggest proponents of SCA listening, and has long felt that it was a greatly underutilized aspect of FM broadcasting--that it should have been programmed and marketed more to the general public years ago, much like the additional HD channels are today.

Also, is there another subcarrier frequency besides the 67 and 92? Thanks.
Click to expand...

67 and 92 are where audio programming is. 57kHz is used for RDS. If there is no audio programming there might be a variety of subcarrier frequencies running data.
 
NHRadio said:
Forgive my ignorance here, but where could one get a tunable SCA receiver? We have some fixed ones we use at the cluster I work at that we use as emergency STL's. Sounds lousy, but it works. Also, is there another subcarrier frequency besides the 67 and 92? Thanks.
Click to expand...

You could take a LF (50-100kHz) FM receiver and couple it to the IF of the main FM receiver. A MC3357 IC or similar would make a fixed SCA rcvr if you upconverted to its 455 IF but you will need proper filtering to keep the higher freqs of the internal IF out of the SCA audio..I have used a Rycom as a LF detector before but they are good for AM or SSB, not a FM subcarrier. The 57 kHz subcarrier is used for RDS pretty much now. The 67 or 92 are the ones used today for audio or signaling (paging, etc)..iirc the old Cue Paging used the 67 subcarrier...but they went bankrupt anyway and most stations had pulled their gear for lack of payment before they filed Chapter whatever!
 
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