HFU HF Underground

Loggings => Satellite, Radiosondes and Other VHF/UHF Signals => TV DX Loggings => Topic started by: Tim Bucknall on September 07, 2018, 0558 UTC

Title: A6 negative offset, who is still analogue on East Coast?
Post by: Tim Bucknall on September 07, 2018, 0558 UTC
Hi Guys,
for 2 months  i've recorded 87.75 with an SDR while beaming at North America (my qth is Northern England) looking for   transatlantic meteor scatter
this morning at 0543 utc i *MIGHT have had something on 87.74 (i'm trying not to get overexcited!)
so who is still on in analogue mode with decent power on A6- on the Eastern Seaboard of North America?

are all the "Frankenstein FMs" in the US on 87.75 zero offset or are some on 87.74?

thank in advance

yours  excitedly :D

Tim Bucknall, Congleton Cheshire, UK






Title: Re: A6 negative offset, who is still analogue on East Coast?
Post by: Tim Bucknall on September 07, 2018, 0711 UTC
likely suspect: CJOH-TV,  Deseronto, ON 10kw audio 
Title: Re: A6 negative offset, who is still analogue on East Coast?
Post by: ChrisSmolinski on September 07, 2018, 1019 UTC
Nice potential catch!
Title: Re: A6 negative offset, who is still analogue on East Coast?
Post by: MDK2 on September 07, 2018, 1508 UTC
Did you have a television image, or just audio?

If it was audio only.... The former television channel six frequency is 87.75 and it's often occupied by radio stations now. I have a Spanish language one here in Denver, KXDP (based in Boulder, actually). The rest of the traditional FM band 88-108 all have an odd number for the first decimal place (87.9, 88.1, 88.3 etc up to 107.9)

Here's a list of American radio stations transmitting on 87.75 MHz. If you got one, it would be an incredible catch because they all appear to be LPFM (low power - I don't know what the highest wattage a LPFM station can use, but the ones I've looked up don't ever seem to be over 100 W, or even as much as that.)

https://en.wikipedia.org/wiki/Channel_6_radio_stations_in_the_United_States

If it was TV, then it seems doubtful that it was American. I think all analogue transmissions have ceased, and Tim Bucknall's suggestion is a good one.
Title: Re: A6 negative offset, who is still analogue on East Coast?
Post by: Tim Bucknall on April 09, 2019, 1733 UTC
Thanks all,
Iíve reluctantly concluded it was a local interference source

Your help was greatly appreciated though
Title: Re: A6 negative offset, who is still analogue on East Coast?
Post by: Tim Bucknall on August 23, 2019, 1732 UTC
 Great list btw,


during the  recent perseids shower i  pointed the aerial at 285 degrees (transatlantic) and recorded 87.75 overnight , nothing ventured nothing gained right?

i got  a blank carrier on 87.750, this time it definitely isn't local noise but is there any reason why anyone would be broadcasting a blank carrier?

it could be Italy off the back of the Aerial but nobody in Italy knows anything about it
another possibility is an Irish pirate

pretty much the only clear bit of band i have is 87.5- 87.9  which is why i'm trying 87.75 rather than something high powered
(though i do have some recordings of 91.7 still to check)

here's some  IQ files recorded overnight on 7th-8th august , the 87.75 signal is weak and best listened to in CW mode
rx was an Elad FDM-S2

for navigation purposes, i have a strong local pest on 88.0
https://mega.nz/#F!Zst1RQYb!8LmjaaQnx-Sb_K4tMMyDYQ