A head scratcher - long distance repeater access through a mountain

[Sbsyncro]

2 hours ago, Lscott said:

You sure you're talking to the repeater that you think you're using?

Some repeaters have remote receivers and transmitters. There is a "voting" system that will route the strongest signal to the transmitter from the various remote receivers.

Also are there any valleys or tunnels around or through the mountain? A valley could be "ducting" the signal around the mountain bouncing the signal off the valley walls. A large tunnel through the mountain could also function as a kind of wave guide at UHF. The later I've heard about where sailors on board large ships had no trouble picking up local FM stations deep inside while docked at a port. The steel passage ways through the ship acted like a huge wave guide at UHF.     

I have not spoken directly with the repeater owner, but have spoken with someone local to it that has his own repeater. We discussed the oddity of being able to make regular contact, and I confirmed with him the location of the repeater.

That being said, I think you might be on to something with the "wave guide" idea.   Check out this enhanced map (enhanced to show slope angles).  It indicates a pretty clear "channel":

[Mikeam]

I have the same thing or similar here in WA state where I can always receive a repeater at 60 miles from me. My base radio only puts out 30 watts and I can hold the repeater open but there is no audible from me but the KG1000 will always RX TX from the same location. There is a small hill between my base and the repeater and a military base to work around. This same repeater also will be heard in Portland at times so I figure it is just the nature of the beast.

[MichaelLAX]

On 3/13/2022 at 8:20 AM, Sbsyncro said:

Yes!  Although I recently heard that they [Jocko’s] didn't make it through COVID lockdowns are are now out of business, sadly.  I have not confirmed this.

 

YaaY!!!

[WyoJoe]

On 3/14/2022 at 10:49 AM, Lscott said:

Also are there any valleys or tunnels around or through the mountain? A valley could be "ducting" the signal around the mountain bouncing the signal off the valley walls. A large tunnel through the mountain could also function as a kind of wave guide at UHF. The later I've heard about where sailors on board large ships had no trouble picking up local FM stations deep inside while docked at a port. The steel passage ways through the ship acted like a huge wave guide at UHF.     

I'm thinking that the signal is going through the Highway 154 corridor, more or less around the mountain, rather than over it. My experience with GMRS is that the signal will go over or around a small hill, but it won't go over or through a large mountain. Although it's largely line of sight, there is some wiggle room, so to speak. Even though it still has to go over the pass, there is likely enough wiggle room to allow the signal to get through.

Glad to hear about Jocko's staying in business. It's a long-standing tradition for many to go there when in the area.

[WyoJoe]

On 3/14/2022 at 10:49 AM, Lscott said:

Also are there any valleys or tunnels around or through the mountain? A valley could be "ducting" the signal around the mountain bouncing the signal off the valley walls. A large tunnel through the mountain could also function as a kind of wave guide at UHF. The later I've heard about where sailors on board large ships had no trouble picking up local FM stations deep inside while docked at a port. The steel passage ways through the ship acted like a huge wave guide at UHF.     

I'm thinking that the signal is going through the Highway 154 corridor, more or less around the mountain, rather than over it. My experience with GMRS is that the signal will go over or around a small hill, but it won't go over or through a large mountain. Although it's largely line of sight, there is some wiggle room, so to speak. Even though it still has to go over the pass, there is likely enough wiggle room to allow the signal to get through.

Glad to hear about Jocko's staying in business. It's a long-standing tradition for many to go there when in the area.

[wayoverthere]

On 3/14/2022 at 1:02 PM, Sbsyncro said:

I have not spoken directly with the repeater owner, but have spoken with someone local to it that has his own repeater. We discussed the oddity of being able to make regular contact, and I confirmed with him the location of the repeater.

That being said, I think you might be on to something with the "wave guide" idea.   Check out this enhanced map (enhanced to show slope angles).  It indicates a pretty clear "channel":

I'll have to remember this as well....quite the view from that corridor, and not a bad drive/ride either.