At 1/21/2006 18:18, you wrote:
>Dave,
>
>That's when a good network analyzer's dynamic range really is important.
>With a DR in excess of 125 dB, the noise floor is not a factor even if
>you're tuning a six-cavity duplexer with 8" or 10" cans- and there is still
>the capability to increase the stim
>http://www.seits.org/duplexer/duplexer.pdf
>
>73, Eric Lemmon WB6FLY
>
>-Original Message-
>
>
>
> ----------------------------
>
> Subject:
> Re: [Repeater-Builder] Re: Duplexer retune / recoax
> From:
http://www.seits.org/duplexer/duplexer.pdf
73, Eric Lemmon WB6FLY
-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Chuck Kelsey
Sent: Saturday, January 21, 2006 6:48 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Dup
s.com
[mailto:[EMAIL PROTECTED] On Behalf Of Jeff DePolo
Sent: Saturday, January 21, 2006 6:21 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Duplexer retune / recoax
Well, my guess is that the high insertion loss you saw was not due to the
incorrect cable lengths *be
Eric,
Can you provide links to these?
Chuck
WB2EDV
Eric Lemmon wrote:
>Jeff,
>
>I'll be the first to admit that reality often contradicts theory. However,
>both EMR and TX-RX have published application notes which support my
>statement.
>
>
>
>
Yahoo! Groups Links
<*> To visit you
> Once a new low-split harness was
> purchased directly from Sinclair (about $125, as I recall) and
> installed, the duplexer tuned up with the expected pass loss of
> about 1.6 dB. The notch attenuation was within a dB of the previous
> value, using the incorrect harness.
Well, my guess is t
Dave,
That's when a good network analyzer's dynamic range really is important.
With a DR in excess of 125 dB, the noise floor is not a factor even if
you're tuning a six-cavity duplexer with 8" or 10" cans- and there is still
the capability to increase the stimulus power. Once I got used to using
: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Duplexer retune / recoax
> The length of the jumper cables between the cans has a profound
> effect upon the insertion loss at the pass frequency, and relatively
> little effect upon the isolation at the notch freque
Jeff DePolo wrote:
>In contrast, for proper reject notch performance, there has to be correct
>phasing between cavities. The notches are effectively shorts at the notch
>frequency, and if they are not repeated at 1/2 wavelength intervals between
>cavities, they will tend to not align when cavi
> The length of the jumper cables between the cans has a profound
> effect upon the insertion loss at the pass frequency, and relatively
> little effect upon the isolation at the notch frequency.
>
> 73, Eric Lemmon WB6FLY
Eric,
I'm curious why you say this, as it contradicts what I would be
PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Duplexer retune / recoax
All this discussion about duplexer tuning and cabling is making me
wonder if I should not order a duplexer for the TKR-750 and just use
separate TX and RX antennas. Most repeaters, of course, op
Some time back I worked with a 155 Mhz Sinclair Duplexer in the 2M band. I
could not get the notches to tune properly, so I added a Type N elbow in one
leg of the circuit. This made the coaxial jumper about 1" longer (bungee
coax) and solved a problem.
I would be much surprised if cables were an
At 1/20/2006 21:27, you wrote:
>All this discussion about duplexer tuning and cabling is making me
>wonder if I should not order a duplexer for the TKR-750 and just use
>separate TX and RX antennas. Most repeaters, of course, operate on a
>specific frequency pair but, since mine will be mobile and
At 1/21/2006 04:48, you wrote:
>If you use UHF male connectors, I don't know where you
>measure from.
I believe it would be the same as for the male Ns (tip to tip). That puts
your signal just inside the can, where the loop should be.
Bob NO6B
Yahoo! Groups Links
<*> To visit your gr
That's EXACTLY what the radio world has been needing
for decades: bungee coax. We already have lossy coax,
and leaky coax. We definitely need "stretchy" coax.
That would make the circle complete.
I love it. You should send that suggestion to Andrew
or maybe even Belden. Make sure the cable you end
All this discussion about duplexer tuning and cabling is making me
wonder if I should not order a duplexer for the TKR-750 and just use
separate TX and RX antennas. Most repeaters, of course, operate on a
specific frequency pair but, since mine will be mobile and could be
set up anywhere,
At 1/20/2006 19:16, you wrote:
> > The length of the jumper cables between the cans has a profound
>effect upon
> > the insertion loss at the pass frequency, and relatively little
>effect upon
> > the isolation at the notch frequency.
>
>Which brings up a fun question..
>How do you know what the r
Dave,
The vast majority of duplexers will work pretty well with the cables close
to the right length. After all, Sinclair offers only two cable harnesses
for their Q-202G BpBr duplexers- one for the 136-150 MHz split, and the
other for the 150-174 MHz split. I may not have the splits correct, bu
be
excessive. YMMV.
73, Eric Lemmon WB6FLY
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Andrew
G.Sent: Friday, January 20, 2006 11:32 AMTo:
Repeater-Builder@yahoogroups.comSubject: Re: [Repeater-Builder] Re:
Duplexer retune / recoax
Have you tested it
Have you tested it into a dummy load? If you were able to achieve a decent amount of isolation on a service monitor, then I wouldn't think you would need to go through the trouble of re-cabling itJust a thought.. Andy
Yahoo! Photos
Ring in the New Year with Photo Calendars. Add ph
20 matches
Mail list logo
