[Repeater-Builder] DB4062 in non-standard application
The local CAP group has a DB4062 duplexer. (6- 8 cans) Somehow they are able to operate a VHF repeater and a packet node all on one antenna using this set of BPBR's. Does anyone have an idea as to how they would have plumbed the duplexer to make this happen? I don't know the CAP frequencies in question, sorry. I would like to do a 2M machine - 147.075+ and APRS - 144.39. I realize I *could* just go to the site and look, but it's at about 3000' and it's snowing like crazy right now. This is not to mention the ICE we had the past two days. Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Rd Boswell, PA 15531
Re: [Repeater-Builder] DB4062 in non-standard application
Scott, IIRC the split on a CAP repeater is very wide; one side is below the 2 meter band and the other is above...148.15 as an output comes to mind with a 143 input. That being the case I would suspect that they probably reconfigured the duplexer to use 1 or more cans for the packet freq and the rest for the repeater since the wider split would not require all 6 cans for proper isolation. Sounds like a trip to the site would make for an interesting snowmobile run. Milt N3LTQ - Original Message - From: Scott Zimmerman n3...@repeater-builder.com To: Repeater-Builder@yahoogroups.com Sent: Thursday, January 08, 2009 4:19 PM Subject: [Repeater-Builder] DB4062 in non-standard application The local CAP group has a DB4062 duplexer. (6- 8 cans) Somehow they are able to operate a VHF repeater and a packet node all on one antenna using this set of BPBR's. Does anyone have an idea as to how they would have plumbed the duplexer to make this happen? I don't know the CAP frequencies in question, sorry. I would like to do a 2M machine - 147.075+ and APRS - 144.39. I realize I *could* just go to the site and look, but it's at about 3000' and it's snowing like crazy right now. This is not to mention the ICE we had the past two days. Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Rd Boswell, PA 15531 Yahoo! Groups Links
Re: [Repeater-Builder] DB4062 in non-standard application
At 1/8/2009 13:19, you wrote: The local CAP group has a DB4062 duplexer. (6- 8 cans) Somehow they are able to operate a VHF repeater and a packet node all on one antenna using this set of BPBR's. Does anyone have an idea as to how they would have plumbed the duplexer to make this happen? Configuring a duplexer for 2 RX 1 TX isn't too hard at all. But 2 in-band TXs are a problem, as you need to keep the 2nd TX out of BOTH the other TX the RX. 2 RXs don't need much isolation between each other. My guess is that if all they're using is the duplexer, they may not have enough isolation between the TXs to prevent generating IMD when both TXs are up. It may work for them, but it might still be dirty. Bob NO6B
