Re: 146.605 MHz signals


Paul Butzi (W7PFB)
 

After listening to a bunch of audio samples on the internet I think I was wrong, it’s not DMR, it sounds more like DSTAR in simplex mode.

If someone has DSTAR experience and can help me set up DSTAR on my Kenwood TH-D74A, well, I’d sure appreciate it.

If someone with a DSTAR radio already set up could give a listen we might know who it is.

-p W7PFB
73, Don’t forget to smile and have fun!

On Apr 13, 2019, at 5:34 PM, Ralph Lease <ralph.lease@...> wrote:

Paul:
I got out my handy dandy direction finding kit we built.  I really think we are hearing 2 separate sources for transmissions (duh, 2 radios transmitting).

First, I can locate on one of the transmissions with the Handi-finder. I can null the tone with the signal to the side of the dipole. The direction of the null puts it on a 0 degree magnetic heading from my 
QTH.  In another part of the transmission, I could not discern the bearing as I could not null out the tone.

Again, the null was off the side of the dipole not the ends for reference.

Just my 2 cents.

73,
Ralph
kc7qxd





On Sat, Apr 13, 2019 at 7:37 AM Paul Butzi (W7PFB) <w7pfb@...> wrote:
I’m pretty sure what we’re hearing, at least on 146.605, is DMR.

Here’s a recording of what DMR sounds like if you listen to it via analog FM:

The transmitter must be quite close to me.  Not long ago, when my station was in crossband repeat, there was one fellow who had a very confused conversation with Ken when my station picked up his transmission of whistles, kerchunks, and other random words and noises (clearly testing some gear and not IDing nor realizing his signal was being crossband repeated to Cougar).  I could pick up his signal on reverse, so he was either using quite a lot of power or else was fairly local to my place.  His analog FM signal was on 146.605.  Sadly I don’t recall his callsign, Robin looked it up and found it belonged to some ham based in Oregon.

I suspect what we’re hearing is the same transmitter.

I also believe this is what DMR sounds like when working through a repeater, the sound for simplex is apparently different.  I’ve done some digging around on various DMR sources but haven’t found any listing for a repeater with either an input or output frequency of 146.605.  But perhaps someone is operating a uncoordinated/unlisted DMR repeater?

I’ve tried to DF the signal usning my HT and Yagi.  the signal is so strong at my QTH that it’s nearly full scale even in the null of the Yagi.  I should finish up my DF kit and give it a whirl.  it does not help that the transmissions are so randomly intermittent and short.

-p W7PFB
73, Don’t forget to smile and have fun!

On Apr 12, 2019, at 5:36 PM, Rowland <k7rwb@...> wrote:

Wow I just heard it here at S9.  It is like Tom describes and does not last very long. About three seconds, three second pause then again about three seconds then stopped.  If Tom and I are both getting it a S9 that is powerful signal.
 
Thanks,
 
Rowland 
 
From: snovarc@groups.io <snovarc@groups.io> On Behalf Of Tom WA7TBP via Groups.Io
Sent: Friday, April 12, 2019 5:34 PM
To: snovarc@groups.io
Subject: [snovarc] 146.605 MHz signals
 

Hello all, 

I have been monitoring 146.605 MHz this afternoon. At my QTH, Tolt HIll, with a unity gain antenna, I am receiving the signals at S9 according to my receiver. It sounds to me as though this is a telemetry type signal. I hear an audible beep, then the "growling" signal starts, then there is an audible beep, and the "growling" stops. This was the sequence of events I heard for over two hours. I was not able to predict the frequency of the signals. I believe we may have a dirty telemetry transmitter somewhere.
 
By the way, I believe I am hearing these signals on other ham frequencies as well. I have been hearing signals like these for about 2 weeks. I haven't been able to see what other frequencies, as I am usually driving and don't want to look down at the radios.
 
Let's keep listening and see if we can find the "hottest" spot for the signals, and maybe do like Shawn said and get out our DF devices.
 
Tom





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