wcpotter

Still not sure what to do, lol. Using LMR type cable for duplexer to antenna goes against everything I have been taught. Sounds like the people who are using rg-58 & rg-8 in the field aren't using it with a single radio & not a repeater setup. help! thanks

I have always understood that LMR type coax is not appropriate for use from the duplexer to the antenna.

Funny how the HOA doesn't allow antennas, but they are ok with the ugly sat dish next door to you. lol

Thanks for all the info. What are you all using for coax from the antenna to repeater in these portable/temporary situations? I'm using 1/2" superflex heliax @ home, but would prefer something more flexible for use in the field.

I have a Icom 45w repeater. Occasionally I will use it for various public events coordination. There will be a few handheld radios out in the field all within 1 mile or less of the repeater. In terms of the antenna...........budget isn't so much of an issue. Something simple to deploy that isn't massive would be ideal. Something that would mount to a tripod & mast would be great. Chris

I have a portable repeater all racked up & ready to go. Any suggestions for the antenna? Chris

I have a local radio shop that will put it on the bench and tune it if need be. Can someone confirm that the LMR-400 cables that are being used to connect to the receive & transmit sides of the duplexer are correct? Thanks Chris

I bypassed the Henry amp, set the transmit radio to high power & noticed no difference in regards to the issue I am having. I have had people out in the field and I am able to receive them loud & clear with the transmitter off, turn the transmitter on & I lose their audio, but still receive the signal. Nothing else is at my location that would cause any interference. All the cabling for the duplexer is rg-214/u except for the output to the receiver & input from the amplifer.......those are lmr-400. I know the rg-214/u is the proper cable to use between the duplexer cavities, antenna input, etc., but Is the LMR-400 ok to use for the receive & transmit sides of the duplexer? If not I'm guessing that could be the problem perhaps? This system was given to me setup this way, so I am working through all the bugs myself. Keep the feedback/tips coming! Thanks

I tried reversing the tx & rx and it got worse, so I have ruled that out. Do duplexers ever "go bad" or is it just out of tune perhaps?

I did a bit more troubleshooting yesterday as I heard someone trying to use the repeater. Same thing, no audio. When I shut the transmit radio off I could hear the user crystal clear, turned the transmitter on & no audio on receive.

Cavity style

It is a telewave duplexer. I tested the receive using non-gmrs uhf frequencies with the duplexer inline & everything worked fine.

I tuned the receiver to a frequency that transmits from about 3 towns away and my system received it loud and clear and passed it through to the transmitter with no issues. I'm beginning to think that the terrain, current antenna height are working against me on the receive side. Wondering if its worth getting a receive preamp.

The system is made up from the following components: TYT TH-9000D for the receiver & transmitter. Transmitter hits the amp with 10 watts drive. Telewave duplexer ID-Omatic 4 controller Henry amplifier

I checked all the equipment last night to make sure it is all set for wideband operation. When I was given the system the receive and transmit side of the duplexer needed to be re-connected, the rest were intact. The duplexer is clearly labeled for receive and transmit. I can only assume it wasn't tuned backwards. Would you suggest swapping the two just in case or would that cause damage? The antenna we have is a Comet CA-712EFC, the same antenna the prior operator used.

My guess is I am having a desense issue, but I'm not 100 percent sure. The repeater works fine until I am about 1 mile away from the antenna site. Once outside of this area the audio from the mobile units stops getting through to the repeater. I know we are still reaching the repeater because we receive the squelch tail after attempting to transmit. The station ID from the controller can be heard loud and clear within a 3 town radius, so I know we are getting good coverage from the transmitter side of the repeater. The duplexer has been tuned, we are using the proper jumpers for the duplexer, we are running 70 feet of 3/8" superflex andrew heliax. Brand new Comet antenna, etc. etc. The only possibility I can seem to find through searching the internet is that there may be a bad jumper at the duplexer. This setup was running at another site with no issues. The only thing that has changed is the feed line and the antenna.

I'm new to heliax cable use also........can someone explain the bend radius and superflex vs standard cable? It's a bit confusing. Never having used it I can't get a sense of how flexible these cables really are. For example.......will either cable be able to go over a roof edge & straight down a outside wall without damaging it? Can it bend @ the entry point of a wall and form a drip loop without damage? Thanks Chris