Just wanted to say thanks for all replys
joel kj4si
com
[mailto:repeater-buil...@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 a
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
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
ha
> 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
rfect
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:
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 du
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 perf
plexer".
73
Gary 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 h
hoogroups.com
Subject: Re: [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,
ups.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
exciter has 22 dB l
al Message-
From: 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 recommendati
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
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
microv
roups.com>>
> To: Repeater-Builder@yahoogroups.com
> <mailto:Repeater-Builder%40yahoogroups.com>
> <mailto:Repeater-Builder%40yahoogroups.com>>
> Sent: Sat Aug 22 10:22:36 2009
> Subject: RE: [Repeater-Builder] isolation
>
>
>
> My CommShop calcu
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-Builder@yahoogroups.com
<mailto:Repeater-Builder
ugust 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,
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
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
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
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 quo
ssage-
From: 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 i
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
anyone know the isolation of a phelps dodge 6 can VHF BpBr duplexer?
Thanks. TG
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