FM Frequency of the Week: 65.75 MHz

[pianoplayer88key]

Ok, now it's my turn. (And if Bongwater can ask about 108.1, I can ask about this one. )

For those of you that have radios that tune down this low (I have the Tecsun PL-606 and PL-380, both of which go down to 64.00 MHz), what are you hearing on this frequency?

As for me, on both my Tecsuns I hear the audio from XHTJB-TV Channel 3 Analog. Reception at my location using a wire antenna plugged into the PL-606 is fair, but only a few dB above the minimum signal level the radio will display. (Due to a broken (and currently removed) whip, there's no signal without the plug-in wire antenna.

So.... am I the only one that's hearing analog audio on 65.75 MHz, or is there anyone else?

And, since Bongwater mentioned 108.1 or up, I'll open it up to a few other frequencies, adding 59.75 MHz, 71.75 MHz, 81.75 MHz and 87.75 MHz to the list. As for me, on 87.75 I get a fair signal from XETV Channel 6 Analog in Tijuana, Baja California. Alternately, if you get no reception on any of those stations, what DO you hear on a radio that will tune below the FM band (as long as the tuning is continuous with the FM band, as in my Tecsuns)?

 

[fybush]

I'm close enough to the border to pull out audio from CKVR channel 3 in Barrie, Ontario...at least until Canadian analog TV goes poof later this year. Also CJOH-TV-6 on 6 from Deseronto, Ontario, when I can get past the overload from my nearby local FM site. In the summer, Global's channel 2 from Bancroft, Ontario is a semi-regular as well.

 

[w9wi]

I'm close enough to the border to pull out audio from CKVR channel 3 in Barrie, Ontario...at least until Canadian analog TV goes poof later this year. Also CJOH-TV-6 on 6 from Deseronto, Ontario, when I can get past the overload from my nearby local FM site. In the summer, Global's channel 2 from Bancroft, Ontario is a semi-regular as well.

Don't count on all the Canadian analog signals going away this fall. The CRTC has decided not to require analog stations in non-mandatory markets to switch to digital, unless they're above channel 51.

Now, CKVR is in a mandatory market, so it *will* have to switch. I'd have to recheck market lists but I don't think Bancroft or Deseronto are going to be required to convert.

My gut feeling is that these analog transmitters will see little or no maintenance though. I think the first time they see a non-trivial failure they're just going to shut them off.

 

[Darth_vader]

Before the Great American NTSC Killoff happened, I'd sometimes either hear a deccent amount of overload from (A) KATU (channel 2) on my ICF36, depending on where I was in the area, or (B) the KWBP/KRCW translator that used to be on channel 4 and has since moved to 5.

All I get on there now is static, since there's nothing on channels 2-4 anymore (save for the paging service that lives near channel 4.)

 

[fybush]

My gut feeling is that these analog transmitters will see little or no maintenance though. I think the first time they see a non-trivial failure they're just going to shut them off.

I'm sure you're right...as we know, they've already tried to kill off Deseronto once.

 

[Buckeyes2001]

From Vermilion, OH: (since the DTV transition)

Of these frequencies, the only frequencies out of these I have heard a signal was on 87.75 MHz of CIII/Paris, ON (A Global TV affiliate) which occasionally shows up here especially in the summer. On 71.75 MHz, I once received some weak E-skip of 2 different French-Canadian TV stations from Québec. (Here is a video of that I uploaded to Youtube: http://www.youtube.com/watch?v=p8z9pd1GnYM). Will be checking for more E-skip and Tropo on these frequencies.

 

[dxer720]

Right now, here is Lake Geneva, all I get is WLFM-LP on 87.75 with a solid stereo & RDS signal.

I've tried channels 3, 4 & 5 on my Degens & Tecsuns last summer, but nothing.

I've have to get tropo from Canada or Es from Mexico or Cuba. Fat chance of that.

 

[MarioMania]

on my TV Sound Radio's..Nothing from Vallejo

But why on the TV audio there's 5 like 87.75, not 87.70

 

[w9wi]

But why on the TV audio there's 5 like 87.75, not 87.70

It wasn't until digitally-tuned radios came along that there was really a difference between 87.75 and 87.70. (an analog-tuned radio could easily tune either one)

The audio frequency is always 4.5MHz higher than the video frequency. (for every analog channel) The video frequency for analog channel 6 is 83.25MHz.

Since the early 1950s, analog TV sets have used a circuit called "intercarrier sound". This circuit depends on the audio-video difference being 4.5MHz. If you were to change that separation to 4.45MHz (which would bring the audio frequency down to 87.70), your audio would be 50KHz "off-frequency" on existing intercarrier sound TV sets. That's enough to cause SERIOUS distortion. (I rather suspect many TVs wouldn't receive the audio at all)

Alternatively, you could move both the sound *and picture* frequencies down by 50KHz -- bringing the video down from 83.25 to 83.20 -- and maintaining the sound-video separation at 4.5MHz. Actually, on most TVs that would probably work OK. But it would result in interference from channel 6 picture signals to channel 5 audio. It might also result in interference to the channel 5 picture. When color was introduced, the color subcarrier frequency was carefully chosen to avoid interference with adjacent-channel video; changing the adjacent video frequency by 50KHz would upset that calculation.

(in any case, moving either frequency by 50KHz would violate FCC standards)

 

[Darth_vader]

It should also be noted that 65.75 is just below the lowest end of the OIRT broadcast band (65.8-74 MHz.) I wonder if anyone using this board from any of the former Soviet countries (at least the ones that are still using the band) have ever heard anything on this frequency....