[Repeater-Builder] isolation

2009-08-26 Thread Joel Hall
Just wanted to say thanks for all replys joel kj4si

Re: [Repeater-Builder] isolation

2009-08-23 Thread Kevin Custer
Eric, and list... Kevin, I agree with your conclusions- provided that the exciter meets your expected performance. I would never assume that I could automatically subtract 22 dB from the proposed isolation, merely because it was a PLL exciter, without knowing for certain that its

Re: [Repeater-Builder] isolation

2009-08-23 Thread Kevin Custer
Gary wrote: Dan Kagabine, the chief engineer at TX-RX systems use to always say that once you have enough isolation to overcome any desense, then any more is a waste of money as it does nothing for you. If you only need 70 db then a 100 db duplexer does nothing more for you than a 70 db

Re: [Repeater-Builder] isolation

2009-08-23 Thread Chuck Kelsey
conditions, you may be unhappy when something moves a bit out of tolerance. Chuck WB2EDV - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, August 23, 2009 9:30 AM Subject: Re: [Repeater-Builder] isolation Gary wrote: Dan

RE: [Repeater-Builder] isolation

2009-08-23 Thread Jeff DePolo
While I'll agree that more isolation, then what is needed to insure no desense is a waste; if this gentleman is suggesting that isolation in reserve is a waste, I strongly disagree. Why? Operating conditions can change - snow and especially ice on the repeater antenna can detune the

Re: [Repeater-Builder] isolation

2009-08-23 Thread MCH
I'll second what Kevin said and add: What if you want to upgrade? If you only purchased what you needed before, it may no longer be adequate for your new system which may have more power or a higher sensitivity receiver. Better to buy extra isolation now and not need it than to buy less and

Re: [Repeater-Builder] isolation

2009-08-23 Thread Mike Morris WA6ILQ
At 06:45 AM 08/23/09, you wrote: I agree with Kevin. You need a little headroom built in for conditions that could change. Equipment ages and changes it's operating characteristics. Temperature swings cause the same issues. Does one need to go overboard? Probably not. But if you happen to be

RE: [Repeater-Builder] isolation

2009-08-23 Thread Gary Schafer
...@yahoogroups.com] On Behalf Of Chuck Kelsey Sent: Sunday, August 23, 2009 8:45 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] isolation I agree with Kevin. You need a little headroom built in for conditions that could change. Equipment ages and changes it's operating

[Repeater-Builder] isolation

2009-08-22 Thread kj4si
Hope someone may have a program,commshop? What I need to know is what amount of isolation with duplexers that is required for a GE m2 reciever with .1...@12db and a m2 pll exciter,100 watt PA on vhf,600kc split?1/2in helix,with 4pole db224 antenna at 70 ft. thanks kj4si

Re: [Repeater-Builder] isolation

2009-08-22 Thread Wesley Bazell
Hi You didn, say Freq. I picked 146.94-146.34 punched in your figures and Got 94.4 Wesley AB8KD - Original Message - From: kj4si To: Repeater-Builder@yahoogroups.com Sent: Saturday, August 22, 2009 9:54 AM Subject: [Repeater-Builder] isolation Hope someone may have

RE: [Repeater-Builder] isolation

2009-08-22 Thread Eric Lemmon
22, 2009 6:55 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] isolation Hope someone may have a program,commshop? What I need to know is what amount of isolation with duplexers that is required for a GE m2 receiver with .1...@12db and a m2 pll exciter,100 watt PA on vhf,600kc

Re: [Repeater-Builder] isolation

2009-08-22 Thread NORM KNAPP
Repeater-Builder@yahoogroups.com Sent: Sat Aug 22 10:22:36 2009 Subject: RE: [Repeater-Builder] isolation My CommShop calculates 99.65 dB is required. I'd definitely be looking at a six-cavity BpBr duplexer for this station. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater

Re: [Repeater-Builder] isolation

2009-08-22 Thread Tony KT9AC
-Builder%40yahoogroups.com Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Sat Aug 22 10:22:36 2009 Subject: RE: [Repeater-Builder] isolation My CommShop calculates 99.65 dB is required. I'd definitely be looking at a six-cavity BpBr duplexer

RE: [Repeater-Builder] isolation

2009-08-22 Thread Eric Lemmon
Of Tony KT9AC Sent: Saturday, August 22, 2009 10:07 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] isolation Other than ordering the software, is there an old-school formula that can be used for this? I been using the decibel-wheel to convert from microvolts to dbm

Re: [Repeater-Builder] isolation

2009-08-22 Thread Kevin Custer
Eric, Are you sure about your six-cavity recommendation? The MASTR II PLL exciter has 22 dB less side-band noise than a typical multiplier exciter - using 600 kHz TX to RX separation. Assuming his preamp isn't driven into a non-linear region (it shouldn't be), a good 4 cavity duplexer, like

RE: [Repeater-Builder] isolation

2009-08-22 Thread Eric Lemmon
: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Kevin Custer Sent: Saturday, August 22, 2009 12:52 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] isolation Eric, Are you sure about your six-cavity recommendation? The MASTR II PLL

Re: [Repeater-Builder] isolation

2009-08-22 Thread Kevin Custer
22, 2009 12:52 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] isolation Eric, Are you sure about your six-cavity recommendation? The MASTR II PLL exciter has 22 dB less side-band noise than a typical multiplier exciter - using 600 kHz TX to RX separation. Assuming

RE: [Repeater-Builder] isolation

2009-08-22 Thread Eric Lemmon
: [Repeater-Builder] isolation Eric, You may have missed the point. While your program calculated a necessary isolation amount of 99.65 dB, using a GE M2 PLL exciter would dictate 77.65 dB of necessary isolation - which is easily obtainable with a quality 4 cavity (okay, 4 large cavity) duplexer

RE: [Repeater-Builder] isolation

2009-08-22 Thread Gary Schafer
K4FMX _ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Kevin Custer Sent: Saturday, August 22, 2009 5:38 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] isolation Eric, You may have missed the point. While

[Repeater-Builder] isolation

2009-05-08 Thread Joel
can Anyone tell me the amount of isolation need on a set of duplexers to run a GE vhf pll exciter with a 100 watt pa. The GE reciever .15 uv @20 db sinad? power at 30 watts,50 watts 70 watts and 100 watts without desense Thanks kj4si

[Repeater-Builder] isolation curves

2009-04-03 Thread phrijjid
i thought i ran across a page with isolation curves on it. i.e. isolation needed at given seperation and given frequencies. maybe just my imagination. i'm interested in isolation needed for 50watt tx output @ 53.45 with rx @ 1.7mHz split thanks chris kb0wlf

RE: [Repeater-Builder] Isolation Curves

2009-04-03 Thread Eric Lemmon
: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of phrijjid Sent: Friday, April 03, 2009 7:41 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Isolation Curves I thought I ran across a page with isolation curves on it, i.e., isolation needed

Re: [Repeater-Builder] isolation curves

2009-04-03 Thread AJ
You were probably looking at the link below: http://www.repeater-builder.com/antenna/separation.html Vertically, for 50 dB of isolation is roughly 100' at 40 Mhz per the sheet. Horizontally, it's 800' for 50 dB, 2500' for 60 dB and 8000' for 70 dB of isolation at 50 MHz per the sheet. Classic

[Repeater-Builder] isolation on Phelps Dodge 506-1

2005-11-23 Thread ab7rs
anyone know the isolation of a phelps dodge 6 can VHF BpBr duplexer? Thanks. TG Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of