You may be locking up with a repeater on the reverse pair during a band opening.
Chuck WB2EDV ----- Original Message ----- From: "offtracks1" <worldroa...@fastmail.fm> To: <Repeater-Builder@yahoogroups.com> Sent: Monday, December 07, 2009 3:48 PM Subject: [Repeater-Builder] Rolling Pipe Sound > Thanks for all the post and for the web site and group. > It's been very helpful to me as I have been setting up my system. > > My repeater system is a Kenwood TKR-750 K2, Telwave TPRD-1556 duplexer set > (6 cavities), A Telwave Isolator on the PA. Running 1/2" Heilax to a > Andrew DB224E antenna. This a repeater at my home as I am on a small hill. > The antenna is about 40 feet vertical and 60 feet horizontally from the > repeater/office. > > It works very well but I have had intermod issue that rears its head now > and then that sounds like rolling pipe or hollow sound. I am runing a PL > on both TX and RX. This sound opens up the receiver even. So my tx pl is > getting back into the system. I have hunted down many noise makers in the > office that could have been helping out. One was the Linksys router. I am > going to replace it anyway as it makes a ton of noise I found. Changing my > network from 100 to 10 on the card speed also reduced the noise levels. > > Still I get the rolling pipe sound now and then and it leaves as fast as > it shows up. If I use my other antenna a Diamond F22 also fed with 1/2 > Heliax I also get the same result. I do use a preamp but it also seems to > not change with or without it. I have even ran it so the receive antenna > is alone and the transmit is the other (split). I still get the rolling > pipes now and then. > > I do have a FM radio station on 92.1 about 4 miles from me that is known > to have a sloppy signal. Could it be that this is mixing with my system > and creating this? > > Looking at getting a DCI Band pass filter on the receiver side but I am > not sure if that is just throwing more money at this project and not > getting anywhere still. > > Just wanted to see if anyone had some ideas? > > Scott KB7DZR > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.709 / Virus Database: 270.14.97/2550 - Release Date: 12/07/09 02:33:00
