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Getting into a repeater, but not getting a return


Borage257
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Can hit the repeater well with some background "snow"(as per the guy on the other end), but can only hear the return with the Monitor button pressed. What would cause a decent repeater hit, but poor return signal?

1. The CTCS tones are programmed correctly

2. Radio is an AT779UV, Antenna rollup Jpole at 15' ( going to add height later)

3. The "trip" is 36 miles "uphill" from my antenna through suburban/town and country foliage etc.

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I would remove the receive CTCSS tone and see if that makes a difference.  It's possible that the repeater isn't actually transmitting the published tone or the signal is so weak that your radio cannot detect the tone.

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WRCI350 had it right.  Remove the receive tones, at least as a diagnostic step.

The fact that you get into the repeater indicates you have the transmit tone correct. The fact that your receiver doesn’t break squelch on receive may point to a mismatch in receive tone. Pressing the Moni button bypasses the receive tone and temporarily turns off squelch.  Turning off tone squelch or setting the receive tone to none and testing will confirm whether it’s the tone. Then you may be able to scan for the right receive tone or live with it by leaving the receive tone clear.

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24 minutes ago, Borage257 said:

It doesn't really, as the night goes on the signal gets stronger.

That could be anything -- 462MHz isn't really affected by ionosphere changes (which is why HF bands tend to get better on lower frequencies as the night goes on).

Wild hypothesis: the repeater is exposed to sunlight and high temperatures during the day, which is causing a deterioration of the repeater output signal. As it cools off in the darkness, the signal improves. Maybe the duplexer is getting detuned, maybe it has some sort of rollback in the finals based upon temperature...

 

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21 hours ago, Borage257 said:

On cooler days/evenings, I can get clear responses from the repeater with tones in place. I've noticed I can get squelch breaking repeater responses when the outside air temperature is less than 90*F. 

That sounds like Tropospheric ducting. UHF doesn't usually get affected like VHF does but it can still happen. IF, that is the case, you cant do anything to make it come in better all the time. Tropospheric ducting is similar to skip on CB. It involves conditions in the sky to cause your signals to travel farther. Google Tropospheric ducting. Its a good read. I love working it. Back in 2001 I remember working Ham Radio Repeaters all over New England clear up into Canada from South Eastern Connecticut on 2 meters. One night in 2002 I sat and talked over a repeater in Virginia from New London CT. 

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22 hours ago, Borage257 said:

@SshannonThe Tones are correct. On cooler days/evenings, I can get clear responses from the repeater with tones in place. I've noticed I can get squelch breaking repeater responses when the outside air temperature is less than 90*F. 

Have you tried getting closer to the repeater to see where both transmit and receive work reliably?  How close do you have to be?

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36 mile to a hill top repeater (the OP did state "uphill") seems a rather short distance for tropo-ducting to be significant. A 400ft tower, from sea level, gives a horizon of 24 miles. http://www.ringbell.co.uk/info/hdist.htm

Put the repeater (even with a short tower) on top of a 1000ft peak and the horizon is 38 miles (and if you account for radio refraction, probably a mile or two more). I'd expect tropo-ducting to be much more "over the horizon" (I remember summers when Detroit TV stations were coming into Grand Rapids -- back in the 70s).

Hmmm, "country foliage" transpiration could be a factor -- much change in humidity as the day changes to night. https://www.researchgate.net/publication/303882023_Force_of_Atmospheric_Humidity_on_UHF_Radio_Signal

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@KAF6045Most of the repeaters in my area are "up hill" from me with their tower footings sitting 100' to 150' above sea level than my house. 

@Sshannon Kinda, When I'm visiting friends at higher elevations (+100' to +150' in relation to my house) i can get better reception. 

Another oddity to throw in my current antenna (rollup slimJim/Jpole on a fiberglass rod) kind of in a corner on my house (a "concave" corner so to speak). There are aluminum gutter in the corner about 18" on one side and 28" on the other. The antenna does not currently clear the roof. 

Another oddity: When i put the radio in my car ( car has a Nagoya UT-72 G magmount) I can hit and receive from another repeater about the same distance from the one in the original post.  

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18 minutes ago, Borage257 said:

@KAF6045Most of the repeaters in my area are "up hill" from me with their tower footings sitting 100' to 150' above sea level than my house. 

@Sshannon Kinda, When I'm visiting friends at higher elevations (+100' to +150' in relation to my house) i can get better reception. 

Another oddity to throw in my current antenna (rollup slimJim/Jpole on a fiberglass rod) kind of in a corner on my house (a "concave" corner so to speak). There are aluminum gutter in the corner about 18" on one side and 28" on the other. The antenna does not currently clear the roof. 

Another oddity: When i put the radio in my car ( car has a Nagoya UT-72 G magmount) I can hit and receive from another repeater about the same distance from the one in the original post.  

How much do you know about the repeater.  Is it possible that the repeater you’re having trouble hearing uses two different antennas, one for transmit and another for receive, at different heights on a tower. Sometimes this is done rather than using a duplexer. 

Also, you mentioned that you can hear another repeater that’s at a similar distance from your car.  Are you saying that with your mobile configuration you can hit both repeaters but only hear from the second one?

Have you tried putting your Nagoya magmount up on your roof on a cookie sheet and using that?

Or put that j-pole up on the roof.  Seems like there are a lot of things you haven’t really tried yet that might solve this problem.

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@SshannonWorking on getting some longer coax to mount the Slimjim (or other antenna) above the ridge line.  I dont have much info on the specifics of the repeater other than the height AGL. I was wondering if it has to do with the car being such a large ground plane. The mag mount ( mounted on my window AC in about the same position) yields similar results to the Slim jim. 

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