Kenwood TKR820 - Cheap duplexer vs seperate antennas

[smokey222]

Have been using the tkr820 repeater with a cheap ebay duplexer and old db404 antenna.  I can't say I've been happy with the results as far as usable coverage.  I have been considering removing the duplexer and adding in a tram 1486 (that I have had laying around) as the second antenna. My simple thinking is that maybe the db404 would be the better receive antenna and the Tram would be the better on the transmit side?  Maybe I am expecting too much, I don't know.  Looking for opinions and insight.  Thank you. Scott

[axorlov]

My understanding is that you still need duplexer (or notch filter) on the receiving antenna, or you need to separate antennas by hundreds of feet, or you're risking to burn something in the receiver.

Now, cheap ebay duplexer on the receiving side combined with some degree of separation (25 feet, 50 feet?) may be on option? I don't know, just thinking out loud.

[WRAK968]

neither option is a good choice.

I started out with a cheap e-bay duplexer (Around $125 if I recall) and it never worked. I was lucky to get two blocks range. Turns out the TX side wasn't being blocked by the duplexer, and instead, the RX side was loaded with desense, causing the repeater to not "See" the incoming traffic.

You'r better off researching Band Pass / Band Reject (BP/BR) duplexers and purchasing one when it becomes available within your price range. I spent about $300 for mine and it drastically improved the range of the repeater. Now my only obstacle is height!

 

You can run two antennas however you will need enough vertical separation, about 30-40 feet worth, to avoid desense and damage to the RX radio.