Frequency Sliding?

[N7OLQ]

I know frequency hopping is a thing, but this is the first time I've run across frequency sliding. It is a thing? What's going on here? It isn't a bad radio transmitter since all the transmissions on this "frequency" do this. Has anyone seen this before? It is a real pain to monitor since wherever the scanner stops the transmissions slides away. The slide on the center of each transmission seems to cover about 25kHz. Modulation is just normal FM. It doesn't really make sense since how would the receiving radios sync with the slide?

 

[dave3825]

It isn't a bad radio transmitter since all the transmissions on this "frequency" do this.

And what happens on other freqs? That's most likely not normal.

 

[ecps92]

I know frequency hopping is a thing, but this is the first time I've run across frequency sliding. It is a thing? What's going on here? It isn't a bad radio transmitter since all the transmissions on this "frequency" do this. Has anyone seen this before? It is a real pain to monitor since wherever the scanner stops the transmissions slides away. The slide on the center of each transmission seems to cover about 25kHz. Modulation is just normal FM. It doesn't really make sense since how would the receiving radios sync with the slide?
View attachment 177501

Likely a bad Repeater, if All transmissions have the issue, all come into the input and as passed thru the Repeater.
Just my WAG

 

[N7OLQ]

And what happens on other freqs? That's most likely not normal.

I have not heard anyone complain that they can't copy, but like I say, it isn't easy to stay with a full conversation or even tell if it is a repeater. I have not observed this phenomena anywhere else in the Federal VHF range.

 

[ecps92]

I have not heard anyone complain that they can't copy, but like I say, it isn't easy to stay with a full conversation or even tell if it is a repeater. I have not observed this phenomena anywhere else in the Federal VHF range.

Any PL on it ??

my last notes show
168.7750 R / 164.9125 in for the BLM as a Temp Repeater for the MOAB Field Office (Circa 2012)

 

[N1FKO]

I know frequency hopping is a thing, but this is the first time I've run across frequency sliding. It is a thing?

You could turn on AFC and see if that improves reception.

 

[N7OLQ]

Any PL on it ??

my last notes show
168.7750 R / 164.9125 in for the BLM as a Temp Repeater for the MOAB Field Office (Circa 2012)

I'm well out of range of Moab. No PL tone observed. The weirdest thing has been the traffic seems to be related railroad operations. Mention of Roper yard about 20 miles north of me, various engine numbers, etc. At first I thought Amtrak, but freq lists show them in normal RR freq. range. Maybe DOT FRA (also doesn't seem likely). Any rail operations that belong on these frequencies? (168.7625 possibly the real frequency)

 

[merlin]

I might suggest this is a mixing thing with over the horizon radar. Although, if you monitor CB channel 6, some of those foreign power stations slide up a few KHz after key down.
I have never seen AWACS sweep like this, so no clue why it is so strong.
Not RR or PUC.
I sometimes see this on HF up to about 65 MHz with no other nearby signals.
Someone doing a little jamming ??

A related thread

 

[ecps92]

I'm well out of range of Moab. No PL tone observed. The weirdest thing has been the traffic seems to be related railroad operations. Mention of Roper yard about 20 miles north of me, various engine numbers, etc. At first I thought Amtrak, but freq lists show them in normal RR freq. range. Maybe DOT FRA (also doesn't seem likely). Any rail operations that belong on these frequencies? (168.7625 possibly the real frequency)

Could be an image, from one of the RR freqs, try searching with 2nd Radio when hearing it.
other potential thoughts put me in too many rabbit holes.

10-04 on MOAB, but it is a BLM allocation, and for AZ/NV the USFS

Happy hunting to nail it down