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Loggings => Utility => Topic started by: ka1iic on May 04, 2013, 2328 UTC

Title: CW signal on 108.75 MHZ
Post by: ka1iic on May 04, 2013, 2328 UTC
108.75 MHZ   CW  2324 UTC  598  about 20 WPM

de KA1IIC Vince
Troy Ohio

Title: Re: CW signal on 108.75 MHZ
Post by: Token on May 05, 2013, 0406 UTC
Possibly VOR (VHF Omni-directional Range), need what the CW is saying to be more sure.

T!
Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 05, 2013, 1638 UTC
what it is sending... well  my CW software won't deal with it because of the same problem I am having coping it by ear.  The signal has a serious back wave at time and a bad 'swing'...  It's worse than trying to copy my first novice signal... hi hi :-) It's on my watch list for sure...

I also have been receiving an AM signal on 114.5 MHZ that sounds like like phonetics but I got tired of trying to dig it out from the noise level after an hour of continuous listening ;-) Yet another to add to my watch list.  Maybe I have been listening to 'spy stations too long <heh>

thanks for the reply.

73
vince Ka1iic Ohio
Title: Re: CW signal on 108.75 MHZ
Post by: skeezix on May 05, 2013, 1729 UTC
There are a few ILS localizers somewhat in the area (assuming you're in Troy) that are on 108.75 MHz:
I-UNI  Albany, OH
I-GWB Auburn, IN
I-GYY  Gary, IN

Dayton has a VOR/DME on 114.5 MHz and its ID is DQN.

Can you make a couple of recordings and post them?

    - skeezix



Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 05, 2013, 1958 UTC
audio... just added a 1 minute bit at:

http://vincewerber.org/swl/108750khz.mp3

also here is a short mp3 of the AM signal on 114500khz:

http://vincewerber.org/swl/114-5-unkn-05-05-13-1527Z.mp3

73 vince ka1iic
Title: Re: CW signal on 108.75 MHZ
Post by: skeezix on May 05, 2013, 2150 UTC
In the second recording, it sounds like a VOR with voice weather broadcasts. You can barely hear the ID in the background and unless I heard incorrectly, its identifying as DQN, so that's the Dayton VOR/DME.

In the first recording, what mode do you have the receiver set to? If CW/SSB, set it to AM and see if that's any better. I can't make out anything in the recording. It does not sound like a normal ILS nor VOR transmission. The navaids (VOR, ILS, NDB) are all AM with MCW for ID.
Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 06, 2013, 1355 UTC
I had it in the CW mode (USB) in the AM mode it simply sound like CW without carrier inserted...  I tried it in all modes and CW is the only one that demods it...  It is very weak.

73 & tnx vince ka1iic
Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 06, 2013, 1447 UTC
Just recorded a much better copy of the signal on 108.75 MHZ... this time with some filtering (I forget I have this stuff to use... me bad)

http://vincewerber.org/swl/108750-fil.mp3

I also did a web search for info on this frequency and...  there are even wireless headphones that can be bought that work on this frequency... hmmmm... imported yes but...  I won't buy them  ;-)

tnx
73 vince ka1iic
Title: Re: CW signal on 108.75 MHZ
Post by: skeezix on May 06, 2013, 2316 UTC
Nice & strong this time, but boy, that sure does sound erratic.

Not sure what it could be without the AM carrier. Its not a VOR or other normal navaid as they don't transmit like that (unless its broken). Navaids  transmit in AM with MCW with a two to four letter ID at a regular interval and not too fast. Your thing is nothing like that at all.

Perhaps some spur from something or maybe some sort of low power telemetry. Or a spy! (that needs to go back to radio class).

Can you hear this all the time?

Also, the VHF navaids (108-118) are horizontally polarized. The VHF comms (118-137) are vertically polarized.

Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 07, 2013, 0118 UTC
It's best early in the morning as this last audio clip shows but it seems to be on 24/7 but much stronger in the morning.

It could be a spur like you say... one reason I am shy about posting 'oddities' is that this is a very highly compressed area, lots of apartments and houses and heaven only knows what electronic devices might be tossing out stuff...  IMHO Part 15 has become a joke...  <sigh>

I have an 'Energizer' battery charger and man does that toss out the noise...  oh yeah and the LED 'fashion lighting' on top of the entertainment system puts out 30+ db of noise from LW up and beyond the FM BCB...  glad it is seldom on... thought I was being smart buying it... <NOT!>

73 and thanks for your input
vince ka1iic
 
Title: Re: CW signal on 108.75 MHZ
Post by: skeezix on May 07, 2013, 0208 UTC
Didn't know the LEDs pumped out the RFI, knew the CFLs do. Good to know. 

Don't have any of them here... CFLs are banned from my house forever and LEDs just made the list (until they prove that they're quiet).

People will probably complain about my incandescents, then I'll turn on my old tube rigs...  ;D
Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 07, 2013, 1456 UTC
CFL's are ok if you like living with hazmat (mercury).. not something to have around children for sure.  Yes the LED's put out tons of RFI and I have yet to find one that operates on AC that doesn't, makes no difference what company name is on the product because this stuff is sub-contracted out to the lowest bidder...  This next winter I will try to de-rfi one of them but I have been told by others that have tried that I will be wasting my time...  but I like challenges <heh>

73 Vince ka1iic
Title: Re: CW signal on 108.75 MHZ
Post by: Token on May 07, 2013, 2025 UTC
I have several LED's here (including both radio desk lamps), and no RFI from them.  I did have LED's that gave me bad RFI, but then I changed brands and have had no issues since then.

T!
Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 08, 2013, 1346 UTC
I have 2 Phillips LED Edison base type that raise h... with all radio and somewhat with the TV...  I'm going to try de-RFIing them this winter...

73
Vince KA1IIC
Title: Re: CW signal on 108.75 MHZ
Post by: ka1iic on May 08, 2013, 1354 UTC
I have several LED's here (including both radio desk lamps), and no RFI from them.  I did have LED's that gave me bad RFI, but then I changed brands and have had no issues since then.

T!

Here is a link to a discussion on all types of LED lighting:

http://forum.allaboutcircuits.com/showthread.php?t=47133

73
Vince ka1iic