Repeater increases signal strength on unrelated frequencies. Can anyone explain why?

[WRZR437]

Hello,

I recently completed a personal repeater build to be utilized in remote locations to increase the coverage of HT's. The repeater is based on (2) Motorola mcs2000's with a duplexer and comet ca-712EFC mounted on a 10' mast. The transmit radio is measuring 32 watts of output with SWR of 1.2. Duplexer is center tuned to 462.625 and uses the standard 5MHZ offset. standard travel tone of 141.3 is programmed on both input and output radios. We set up the repeater in a remote location in the mountains west of Denver this weekend to perform some testing and noticed that when the repeater was powered up, we were able to clearly reach a local front range repeater on completely different frequency (462.725). Both our handheld and truck radios were able to reach the 725 repeater but only when my personal 625 repeater was powered on. As soon and the power was shut off to the 625 repeater, The 725 repeater became unreachable. we observed the 625 repeater to make sure it wasn't being activated or retransmitting on the 725 and confirmed it was not. The group was left baffled by how the 625 repeater was seemingly boosting the signal of the other radios on a completely different frequency. Can anyone offer an explanation or theory on what may be happening here?

 

Thanks

[Guest]

I do believe it’s the comet 712efc.   It seams to have super mistical powers that can not be explained by mortal man.    
 

I have no idea from a technical stand point, however I have a base station (no repeater) with a 712efc and now I can transmit further with all my HTs in the property.  I don’t know?  I’m sure some rf radio nerd can tell us why this is the case or tell us why we are wrong. 

[WRWE456]

Would be interesting to know the range of the enhancement from the repeater. Did you test to see how far away you still get an improvement? Does it drop off gradually as you move away?

[WRUU653]

48 minutes ago, WRXP381 said:

I do believe it’s the comet 712efc.   It seams to have super mistical powers that can not be explained by mortal man.    
 

I have no idea from a technical stand point, however I have a base station (no repeater) with a 712efc and now I can transmit further with all my HTs in the property.  I don’t know?  I’m sure some rfvradio nerd can tell us why this is the case or tell us why we are wrong. 

Looks like a 9 dbi gain antenna. I’m guessing that doesn’t hurt the PFM (pure fn magic). I like my Comet mobile antenna.

[WRWE456]

Just thinking out loud here. Could it be that the proximity to the bigger antenna is amplifying the signal from the other antennas? They are made for the same frequencies. We are talking about electromagnetic radiation after all. An electromagnetic coupling in close proximity.

[quarterwave]

Same Input PL's on both repeaters? How about swapping antennae, if they are in same site. Maybe put a temp antenna on the new one and see if it acts the same.