RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[larryjspamme...@teleport.com]

>From the Repeater-Builder website:

"WACOM and Remec

WACOM started out as Waco Communications in Waco, Texas. At some point WACOM 
was bought by Remec, and in November of 2001 was sold to TX-RX."

 
TX-RX has since been purchased by Bird Technologies Group. I've tried several 
times to contact them about some replacement cables, etc. for some used TX/RX 
VHF Repeater Duplexers, and have received no response except for one reply that 
said something like "I've passed your request for information to our 
engineering group, who will be contacting you with the information you need". I 
never heard nything further, after several months. 

But several weeks ago, we were able to order a brand-new TX/RX 420-MHz 4-cavity 
duplexer from Bird Technologies for a 420-MHz link transceiver, although it 
hasn't arrived yet (it's a "Special Order" item).

Larry



-Original Message- 
From: Steven M Hodell 
Sent: Sep 9, 2010 11:10 AM 
To: Repeater-Builder@yahoogroups.com 
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question 

  





WACOM was bought out my Telewave and there tech support staff is very helpful…

http://telewave.com/

You can cross reference your older Wacom cavities with their new product line 
at these links:

http://www.telewave.com/pricelist/wacom.html

http://www.telewave.com/pricelist/duplexers.html





From: Repeater-Builder@yahoogroups.com 
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of 
larryjspamme...@teleport.com
Sent: Thursday, September 09, 2010 11:04 AM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question

  



WACOM hasn't been in business for some years now. Good luck contacting them 
directly!

-Original Message- 
From: Richard Kelly 
Sent: Sep 8, 2010 9:18 PM 
To: repeater-builder@yahoogroups.com 
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question 

Good evening Eric,

Maybe this is why when the trasmit power is dropped to the 20-50 watt range, 
the receive opens way up like it should. However, according to the spec sheets 
regarding the Wacom SP-639 Duplexer, it is rated for 200 watts. So, again, not 
sure what's going on. We will be trying other things such as adding a second 
ground rod outside the shack instead of the single one we use now. We will also 
try isolating the amp some more and replacing the coax feed line with hard 
line. Thank you very much. We will be contacting Wacom directly tomorrow.

Rich Kelly, W2RRK

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Steven M Hodell]

WACOM was bought out my Telewave and there tech support staff is very helpful…

 

http://telewave.com/

 

You can cross reference your older Wacom cavities with their new product line 
at these links:

 

http://www.telewave.com/pricelist/wacom.html

 

http://www.telewave.com/pricelist/duplexers.html

 

 

 

From: Repeater-Builder@yahoogroups.com 
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of 
larryjspamme...@teleport.com
Sent: Thursday, September 09, 2010 11:04 AM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question

 

  

WACOM hasn't been in business for some years now. Good luck contacting them 
directly!

-Original Message- 
From: Richard Kelly 
Sent: Sep 8, 2010 9:18 PM 
To: repeater-builder@yahoogroups.com 
<mailto:repeater-builder%40yahoogroups.com>  
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question 

Good evening Eric,

Maybe this is why when the trasmit power is dropped to the 20-50 watt range, 
the receive opens way up like it should. However, according to the spec sheets 
regarding the Wacom SP-639 Duplexer, it is rated for 200 watts. So, again, not 
sure what's going on. We will be trying other things such as adding a second 
ground rod outside the shack instead of the single one we use now. We will also 
try isolating the amp some more and replacing the coax feed line with hard 
line. Thank you very much. We will be contacting Wacom directly tomorrow.

Rich Kelly, W2RRK

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[larryjspamme...@teleport.com]

WACOM hasn't been in business for some years now. Good luck contacting them 
directly!


-Original Message- 
From: Richard Kelly 
Sent: Sep 8, 2010 9:18 PM 
To: repeater-builder@yahoogroups.com 
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question 

  



Good evening Eric,
 
Maybe this is why when the trasmit power is dropped to the 20-50 watt range, 
the receive opens way up like it should.  However, according to the spec sheets 
regarding the Wacom SP-639 Duplexer, it is rated for 200 watts.  So, again, not 
sure what's going on.  We will be trying other things such as adding a second 
ground rod outside the shack instead of the single one we use now.  We will 
also try isolating the amp some more and replacing the coax feed line with hard 
line.  Thank you very much.  We will be contacting Wacom directly tomorrow.
 
Rich Kelly, W2RRK

 

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[Chuck Kelsey]

4 cans will do it. Preamp may or may not be of any use depending on noise 
floor. Your bigger problem is all the noise that a mobile encounters these 
days. Sometimes it's tough to hear the repeater through all the crap that's 
out there.

Chuck
WB2EDV



- Original Message - 
From: "NORM KNAPP" 
To: 
Sent: Thursday, September 09, 2010 3:04 AM
Subject: Re: [Repeater-Builder] Wacom WP-639 Duplexer question


> Oh drat! I thought I was getting away with something :-)
> I am about to start on a 6m mastr ii with 1 meg split. It is a 110 watt 
> cont duty station I am converting to a repeater. I don't think the exciter 
> is a pll, way too many cans on the board and small icom About how much 
> isolation will I need there? I don't know if I have a preamp for this one 
> or not... But if I do, I would try to run it.
> 73
>
> - Original Message -
> From: Repeater-Builder@yahoogroups.com 
> To: Repeater-Builder@yahoogroups.com 
> Sent: Wed Sep 08 23:08:38 2010
> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question
>
>
>
>
> The PLL exciter is why you're having such good success running a 4-cavity
> duplexer. If you had a PM exciter, chances are you'd be experiencing
> desense. The PLL exciter produces about 22 dB less noise at 600 kHz 
> offset,
> reducing the noise supression requirement of the duplexer by a like 
> amount.
>
> See: http://www.repeater-builder.com/pdf/GE_Isolation_Curves.pdf
>
> The OP also mentioned he was using a preamp - that's not helping his
> situation either. Even with a good receiver he's probably on the edge of
> crunching it with only a 4-pack. Personally, I'd never run a preamp with
> nothing but a 4-cavity duplexer on 2m, but if it works for you, God 
> bless...
>
> A Q202G gives more isolation than a WP639 from what I've seen/measured, in
> part because the cavities are larger diameter (I think they're 7" versus
> 5"?).
>
> --- Jeff WN3A
>
>
>> -Original Message-
>> From: Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> [mailto:Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of NORM KNAPP
>> Sent: Wednesday, September 08, 2010 11:38 PM
>> To: Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> Subject: Re: [Repeater-Builder] Wacom WP-639 Duplexer question
>>
>>
>>
>> I got a set of 4 sinclair cans, like a Q202g on a GE mastr II
>> running 100 watts with pll exciter and GE preamp with no
>> desense. Antenna is roughly 300' away fed with LDF7-50A. Is
>> this a miracle or typical?
>>
>> - Original Message - 
>> From: Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> > <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com> >
>> To: Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> > <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com> >
>> Sent: Wed Sep 08 20:10:44 2010
>> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question
>>
>>
>>
>> I'm not surprised- you're asking too much of a duplexer that
>> has four 5"
>> cans. According to my CommShop program, a duplexer with an 80
>> dB spec is
>> more suitable with transmitter power in the 10-15 watt range,
>> assuming a
>> solid-state PA and a receiver sensitivity around 0.35 uV at
>> 12 dB SINAD. On
>> a 100 watt repeater, I'd expect something like a WP-642,
>> which has six 8"
>> cans. BTDT, got the T-shirt and mug...
>>
>> 73, Eric Lemmon WB6FLY
>>
>>
>> -Original Message- 
>> From: Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> [mailto:Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of RichardK
>> Sent: Wednesday, September 08, 2010 3:11 PM
>> To: Repeater-Builder@yahoogroups.com 
>> <mailto:Repeater-Builder%40yahoogroups.com>
>> <mailto:Repeater-Builder%40yah

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Leroy A. M. Baptiste]

Hi Scott, can you give me some more information on
circulators, or where can I get such information
and prices.

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On
Behalf Of DCFluX
Sent: Thursday, September 09, 2010 2:03 AM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Wacom WP-639
Duplexer question

  

An additional 20dB of isolation can be realized by
replacing the
antenna Tee connector with a circulator. Port A to
B tuned to the TX
frequency, Port B to C tuned to the RX frequency.
Connect TX to port
A, antenna to B, Receiver to C.

I'm using a set of WP-639 and with this setup I am
seeing approx 102dB
of rejection from the TX to RX port and 97dB the
other way.

On Wed, Sep 8, 2010 at 8:40 PM, Scott Zimmerman
mailto:n3xcc%40repeater-builder.com> > wrote:
> Rich,
>
> The short answer is: You need to find a bigger
duplexer. Four 8" cans
> would work well such as a Wacom WP-641. You
could simply call and order
> one if Wacom was still in business. (RIP)
Unfortunately Tx/Rx bought
> them years ago for the name and to quash
competition. They can be found
> occasionally for around $600 or so on the used
market.
>
> Other alternatives are as follows:
> 1) You can use two antennas and split the 639
duplexer so that 2 cans
> are in series between the TX and the TX antenna,
and the other two are
> in series between the RX and the RX antenna.
Terry WX3M a list member is
> doing this with VERY good results on one of his
VHF machines. Of course
> this involves the expense of additional feedline
and a second antenna. I
> think you said you had this machine on an 80'
mast. 50' or so of
> vertical isolation coupled with the additional
isolation of splitting
> the duplexer *may* be enough isolation to get
rid of all the desense. TX
> goes on bottom, RX on top.
>
> 2) Buy additional Band Pass / Band Reject (BPBR)
cans. You can add these
> additional cans between the Tx and/or Rx and the
duplexer. These cans
> will give additional isolation. Even if you can
find just Pass or Notch
> cavities, tune them and put them in the correct
place.
>
> With both of the above options, you are looking
to add to the isolation
> between your transmitter and receiver. You'll
find you'll do best by
> adding cans to your transmitter that notch
side-band noise at your
> receiver's frequency. In other words, do what
you can to insure your
> receiver is not hearing your own transmitter's
sideband noise on it's
> input. Pass cans tuned to the TX frequency or
NOTCH cavities tuned to
> your *RX* frequency placed in the transmit line
are your best hope.
>
> Good luck,
> Scott
>
>
>
> Scott Zimmerman
> Amateur Radio Call N3XCC
> 474 Barnett Road
> Boswell, PA 15531
>

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[NORM KNAPP]

Oh drat! I thought I was getting away with something :-)
I am about to start on a 6m mastr ii with 1 meg split. It is a 110 watt cont 
duty station I am converting to a repeater. I don't think the exciter is a pll, 
way too many cans on the board and small icom About how much isolation will 
I need there? I don't know if I have a preamp for this one or not... But if I 
do, I would try to run it.
73

- Original Message -
From: Repeater-Builder@yahoogroups.com 
To: Repeater-Builder@yahoogroups.com 
Sent: Wed Sep 08 23:08:38 2010
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question

  


The PLL exciter is why you're having such good success running a 4-cavity
duplexer. If you had a PM exciter, chances are you'd be experiencing
desense. The PLL exciter produces about 22 dB less noise at 600 kHz offset,
reducing the noise supression requirement of the duplexer by a like amount.

See: http://www.repeater-builder.com/pdf/GE_Isolation_Curves.pdf

The OP also mentioned he was using a preamp - that's not helping his
situation either. Even with a good receiver he's probably on the edge of
crunching it with only a 4-pack. Personally, I'd never run a preamp with
nothing but a 4-cavity duplexer on 2m, but if it works for you, God bless...

A Q202G gives more isolation than a WP639 from what I've seen/measured, in
part because the cavities are larger diameter (I think they're 7" versus
5"?).

--- Jeff WN3A


> -Original Message-
> From: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> [mailto:Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of NORM KNAPP
> Sent: Wednesday, September 08, 2010 11:38 PM
> To: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com> 
> Subject: Re: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
> 
> 
> I got a set of 4 sinclair cans, like a Q202g on a GE mastr II 
> running 100 watts with pll exciter and GE preamp with no 
> desense. Antenna is roughly 300' away fed with LDF7-50A. Is 
> this a miracle or typical? 
> 
> - Original Message - 
> From: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> mailto:Repeater-Builder%40yahoogroups.com> 
>  
> <mailto:Repeater-Builder%40yahoogroups.com> > 
> To: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> mailto:Repeater-Builder%40yahoogroups.com> 
>  
> <mailto:Repeater-Builder%40yahoogroups.com> > 
> Sent: Wed Sep 08 20:10:44 2010 
> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question 
> 
> 
> 
> I'm not surprised- you're asking too much of a duplexer that 
> has four 5" 
> cans. According to my CommShop program, a duplexer with an 80 
> dB spec is 
> more suitable with transmitter power in the 10-15 watt range, 
> assuming a 
> solid-state PA and a receiver sensitivity around 0.35 uV at 
> 12 dB SINAD. On 
> a 100 watt repeater, I'd expect something like a WP-642, 
> which has six 8" 
> cans. BTDT, got the T-shirt and mug... 
> 
> 73, Eric Lemmon WB6FLY 
> 
> 
> -Original Message- 
> From: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> <mailto:Repeater-Builder%40yahoogroups.com> 
> [mailto:Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of RichardK 
> Sent: Wednesday, September 08, 2010 3:11 PM 
> To: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> <mailto:Repeater-Builder%40yahoogroups.com> 
> Subject: [Repeater-Builder] Wacom WP-639 Duplexer question 
> 
> Good evening, our club has a Wacom WP-639 four can duplexer 
> as part of our 
> repeater system. Input Fq is 147.915 and Output Fq is 
> 147.315. We have a 
> 600kHz (+) offset. Very simply, our main problem is when we run the 
> transmitter at full power 100 watts, there is a HUGE desense 
> on the receive 
> side of things. When we drop the transmitter power level to 
> around 20-50 
> watts, the receive side opens WAY up to a large area where 
> people can get 
> into the repeater. As we begin to bring up the transmitter 
> power, "white 
> noise" begins to appear and the receive side starts to 
> desense again. 

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[DCFluX]

An additional 20dB of isolation can be realized by replacing the
antenna Tee connector with a circulator. Port A to B tuned to the TX
frequency, Port B to C tuned to the RX frequency. Connect TX to port
A, antenna to B, Receiver to C.

I'm using a set of WP-639 and with this setup I am seeing approx 102dB
of rejection from the TX to RX port and 97dB the other way.

On Wed, Sep 8, 2010 at 8:40 PM, Scott Zimmerman
 wrote:
> Rich,
>
> The short answer is: You need to find a bigger duplexer. Four 8" cans
> would work well such as a Wacom WP-641. You could simply call and order
> one if Wacom was still in business. (RIP) Unfortunately Tx/Rx bought
> them years ago for the name and to quash competition. They can be found
> occasionally for around $600 or so on the used market.
>
> Other alternatives are as follows:
> 1) You can use two antennas and split the 639 duplexer so that 2 cans
> are in series between the TX and the TX antenna, and the other two are
> in series between the RX and the RX antenna. Terry WX3M a list member is
> doing this with VERY good results on one of his VHF machines. Of course
> this involves the expense of additional feedline and a second antenna. I
> think you said you had this machine on an 80' mast. 50' or so of
> vertical isolation coupled with the additional isolation of splitting
> the duplexer *may* be enough isolation to get rid of all the desense. TX
> goes on bottom, RX on top.
>
> 2) Buy additional Band Pass / Band Reject (BPBR) cans. You can add these
> additional cans between the Tx and/or Rx and the duplexer. These cans
> will give additional isolation. Even if you can find just Pass or Notch
> cavities, tune them and put them in the correct place.
>
> With both of the above options, you are looking to add to the isolation
> between your transmitter and receiver. You'll find you'll do best by
> adding cans to your transmitter that notch side-band noise at your
> receiver's frequency. In other words, do what you can to insure your
> receiver is not hearing your own transmitter's sideband noise on it's
> input. Pass cans tuned to the TX frequency or NOTCH cavities tuned to
> your *RX* frequency placed in the transmit line are your best hope.
>
> Good luck,
> Scott
>
>
>
> Scott Zimmerman
> Amateur Radio Call N3XCC
> 474 Barnett Road
> Boswell, PA 15531
>

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Jeff DePolo]

The PLL exciter is why you're having such good success running a 4-cavity
duplexer.  If you had a PM exciter, chances are you'd be experiencing
desense.  The PLL exciter produces about 22 dB less noise at 600 kHz offset,
reducing the noise supression requirement of the duplexer by a like amount.


See: http://www.repeater-builder.com/pdf/GE_Isolation_Curves.pdf

The OP also mentioned he was using a preamp - that's not helping his
situation either.  Even with a good receiver he's probably on the edge of
crunching it with only a 4-pack.  Personally, I'd never run a preamp with
nothing but a 4-cavity duplexer on 2m, but if it works for you, God bless...

A Q202G gives more isolation than a WP639 from what I've seen/measured, in
part because the cavities are larger diameter (I think they're 7" versus
5"?).

--- Jeff WN3A
 

> -Original Message-
> From: Repeater-Builder@yahoogroups.com 
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of NORM KNAPP
> Sent: Wednesday, September 08, 2010 11:38 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
>   
> 
> I got a set of 4 sinclair cans, like a Q202g on a GE mastr II 
> running 100 watts with pll exciter and GE preamp with no 
> desense. Antenna is roughly 300' away fed with LDF7-50A. Is 
> this a miracle or typical? 
> 
> - Original Message - 
> From: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
>  <mailto:Repeater-Builder%40yahoogroups.com> > 
> To: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
>  <mailto:Repeater-Builder%40yahoogroups.com> > 
> Sent: Wed Sep 08 20:10:44 2010 
> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question 
> 
> 
> 
> I'm not surprised- you're asking too much of a duplexer that 
> has four 5" 
> cans. According to my CommShop program, a duplexer with an 80 
> dB spec is 
> more suitable with transmitter power in the 10-15 watt range, 
> assuming a 
> solid-state PA and a receiver sensitivity around 0.35 uV at 
> 12 dB SINAD. On 
> a 100 watt repeater, I'd expect something like a WP-642, 
> which has six 8" 
> cans. BTDT, got the T-shirt and mug... 
> 
> 73, Eric Lemmon WB6FLY 
> 
> 
> -Original Message- 
> From: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> [mailto:Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of RichardK 
> Sent: Wednesday, September 08, 2010 3:11 PM 
> To: Repeater-Builder@yahoogroups.com 
> <mailto:Repeater-Builder%40yahoogroups.com>  
> <mailto:Repeater-Builder%40yahoogroups.com> 
> Subject: [Repeater-Builder] Wacom WP-639 Duplexer question 
> 
> Good evening, our club has a Wacom WP-639 four can duplexer 
> as part of our 
> repeater system. Input Fq is 147.915 and Output Fq is 
> 147.315. We have a 
> 600kHz (+) offset. Very simply, our main problem is when we run the 
> transmitter at full power 100 watts, there is a HUGE desense 
> on the receive 
> side of things. When we drop the transmitter power level to 
> around 20-50 
> watts, the receive side opens WAY up to a large area where 
> people can get 
> into the repeater. As we begin to bring up the transmitter 
> power, "white 
> noise" begins to appear and the receive side starts to 
> desense again. All 
> the cables have been switched to double sheilded cables and 
> all the same 
> wavelength in length. We have the duplexer seperated & 
> sheilded from the 
> transmitter & preamp parts. We have not replaced the antenna 
> feed coax with 
> double sheilded coax yet. Antenna is a Hustler G7 atop a 55' 
> mast. The 
> duplexer was retuned just over 1 year ago. Any suggestions as 
> to what we 
> could look into next? Some of us believe the problem is with 
> the tuning of 
> the duplexer receive cans. Thank you very much. 
> 
> 
> 
> 
> 
> 
> 
> 

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Ken Arck]

At 08:21 PM 9/8/2010, n...@no6b.com wrote:




Replacing copper-braided coax with RG-214 or hardline is hardly a waste of
time.



<--Notice I said:

>More grounding and replacing coax with hardline (unless your coax
>isn't doubleshield to start with) will buy you nothing.

I was assuming he wasn't running something along the lines of RG-8 
but I did think to qualify that.


Ken

--
President and CTO - Arcom Communications
Makers of repeater controllers and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net
"We don't just make 'em. We use 'em!"

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[Scott Zimmerman]

Rich,

The short answer is: You need to find a bigger duplexer. Four 8" cans 
would work well such as a Wacom WP-641. You could simply call and order 
one if Wacom was still in business. (RIP) Unfortunately Tx/Rx bought 
them years ago for the name and to quash competition. They can be found 
occasionally for around $600 or so on the used market.

Other alternatives are as follows:
1) You can use two antennas and split the 639 duplexer so that 2 cans 
are in series between the TX and the TX antenna, and the other two are 
in series between the RX and the RX antenna. Terry WX3M a list member is 
doing this with VERY good results on one of his VHF machines. Of course 
this involves the expense of additional feedline and a second antenna. I 
think you said you had this machine on an 80' mast. 50' or so of 
vertical isolation coupled with the additional isolation of splitting 
the duplexer *may* be enough isolation to get rid of all the desense. TX 
goes on bottom, RX on top.

2) Buy additional Band Pass / Band Reject (BPBR) cans. You can add these 
additional cans between the Tx and/or Rx and the duplexer. These cans 
will give additional isolation. Even if you can find just Pass or Notch 
cavities, tune them and put them in the correct place.

With both of the above options, you are looking to add to the isolation 
between your transmitter and receiver. You'll find you'll do best by 
adding cans to your transmitter that notch side-band noise at your 
receiver's frequency. In other words, do what you can to insure your 
receiver is not hearing your own transmitter's sideband noise on it's 
input. Pass cans tuned to the TX frequency or NOTCH cavities tuned to 
your *RX* frequency placed in the transmit line are your best hope.

Good luck,
Scott



Scott Zimmerman
Amateur Radio Call N3XCC
474 Barnett Road
Boswell, PA 15531

On 9/8/2010 9:52 PM, Richard Kelly wrote:
>
>
> Hello again Ken,
>
> Thank you for replying with more info, we appreciate it. My email
> address if you want to get off this posting is w2...@arrl.net
> 
>
> How would we go about providing MORE isolation than what we have done so
> far?
>
> Rich Kelly W2RRK

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[NORM KNAPP]

I got a set of 4 sinclair cans, like a Q202g on a GE mastr II running 100 watts 
with pll exciter and GE preamp with no desense. Antenna is roughly 300' away 
fed with LDF7-50A. Is this a miracle or typical?

- Original Message -
From: Repeater-Builder@yahoogroups.com 
To: Repeater-Builder@yahoogroups.com 
Sent: Wed Sep 08 20:10:44 2010
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question

  

I'm not surprised- you're asking too much of a duplexer that has four 5"
cans. According to my CommShop program, a duplexer with an 80 dB spec is
more suitable with transmitter power in the 10-15 watt range, assuming a
solid-state PA and a receiver sensitivity around 0.35 uV at 12 dB SINAD. On
a 100 watt repeater, I'd expect something like a WP-642, which has six 8"
cans. BTDT, got the T-shirt and mug...

73, Eric Lemmon WB6FLY


-Original Message-
From: Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com> 
[mailto:Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of RichardK
Sent: Wednesday, September 08, 2010 3:11 PM
To: Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com> 
Subject: [Repeater-Builder] Wacom WP-639 Duplexer question

Good evening, our club has a Wacom WP-639 four can duplexer as part of our
repeater system. Input Fq is 147.915 and Output Fq is 147.315. We have a
600kHz (+) offset. Very simply, our main problem is when we run the
transmitter at full power 100 watts, there is a HUGE desense on the receive
side of things. When we drop the transmitter power level to around 20-50
watts, the receive side opens WAY up to a large area where people can get
into the repeater. As we begin to bring up the transmitter power, "white
noise" begins to appear and the receive side starts to desense again. All
the cables have been switched to double sheilded cables and all the same
wavelength in length. We have the duplexer seperated & sheilded from the
transmitter & preamp parts. We have not replaced the antenna feed coax with
double sheilded coax yet. Antenna is a Hustler G7 atop a 55' mast. The
duplexer was retuned just over 1 year ago. Any suggestions as to what we
could look into next? Some of us believe the problem is with the tuning of
the duplexer receive cans. Thank you very much.

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[no6b]

At 9/8/2010 18:24, you wrote:
>At 06:18 PM 9/8/2010, Richard Kelly wrote:
> >
> >
> >  We will be trying other things such as adding a second ground rod
> > outside the shack instead of the single one we use now.  We will
> > also try isolating the amp some more and replacing the coax feed
> > line with hard line.
>
>
><--That is a complete waste of time as that is not the problem. Your
>duplexer simply cannot provide enough isolation for the power level
>you're trying to run.
>
>More grounding and replacing coax with hardline (unless your coax
>isn't doubleshield to start with) will buy you nothing.

Replacing copper-braided coax with RG-214 or hardline is hardly a waste of 
time.  The duplexer isolation may not be quite enough, but that can be 
easily remedied by adding an extra pass cavity to the TX.  Just another 10 
to 15 dB of TX noise suppression is likely all you need.  RG-8, RG-213 or 
LMR-400 antenna feed, OTOH, will make any duplexer moot due to all the 
desense it will generate, sooner or later.

Bob NO6B

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Richard Kelly]

Hello again Ken,
 
Thank you for replying with more info, we appreciate it.  My email address if 
you want to get off this posting is w2...@arrl.net 
 
How would we go about providing MORE isolation than what we have done so far?  
 
Rich Kelly W2RRK

 x


 
> To: Repeater-Builder@yahoogroups.com
> From: ah...@ah6le.net
> Date: Wed, 8 Sep 2010 18:24:41 -0700
> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
> At 06:18 PM 9/8/2010, Richard Kelly wrote:
> >
> >
> > We will be trying other things such as adding a second ground rod 
> > outside the shack instead of the single one we use now. We will 
> > also try isolating the amp some more and replacing the coax feed 
> > line with hard line.
> 
> 
> <--That is a complete waste of time as that is not the problem. Your 
> duplexer simply cannot provide enough isolation for the power level 
> you're trying to run.
> 
> More grounding and replacing coax with hardline (unless your coax 
> isn't doubleshield to start with) will buy you nothing.
> 
> Ken
> 
> --
> President and CTO - Arcom Communications
> Makers of repeater controllers and accessories.
> http://www.arcomcontrollers.com/
> Authorized Dealers for Kenwood and Telewave and
> we offer complete repeater packages!
> AH6LE/R - IRLP Node 3000
> http://www.irlp.net
> "We don't just make 'em. We use 'em!"
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
  

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[Joe]

 I'm afraid your wasting your time.  According to the document for the 
Wacom 639 duplexer, this is what it says:


MIN. FREQ. SPACING: 600 KHz
POWER: TO 200 WATTS

Notice that it says "TO 200 watts".  That would be if you were at 2MHz 
of spacing or more.  You are only at 600KHz spacing, so you power level 
will be much less.  I know it's not what you want to hear, but I believe 
you have the wrong duplexer for a 100 watt solid state repeater.


73, Joe, K1ike

On 9/8/2010 9:18 PM, Richard Kelly wrote:



Good evening Eric,

Maybe this is why when the trasmit power is dropped to the 20-50 watt 
range, the receive opens way up like it should.  However, according to 
the spec sheets regarding the Wacom SP-639 Duplexer, it is rated for 
200 watts.  So, again, not sure what's going on.  We will be trying 
other things such as adding a second ground rod outside the shack 
instead of the single one we use now.  We will also try isolating the 
amp some more and replacing the coax feed line with hard line.  Thank 
you very much.  We will be contacting Wacom directly tomorrow.


Rich Kelly, W2RRK

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Mike Besemer (WM4B)]

Rich,

 

Eric speaks the truth.  The will HANDLE 200 watts without arcing, etc, but
do not provide nearly enough isolation at 600 KHz spacing to handle 100
watts.  For a 35 watt transmitter, I run cans that provide around 96 dB of
isolation. the 85 dB your cans can provide just ain't gonna cut it. 

 

73,

 

Mike

WM4B

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Richard Kelly
Sent: Wednesday, September 08, 2010 9:19 PM
To: repeater-builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question

 

  

Good evening Eric,
 
Maybe this is why when the trasmit power is dropped to the 20-50 watt range,
the receive opens way up like it should.  However, according to the spec
sheets regarding the Wacom SP-639 Duplexer, it is rated for 200 watts.  So,
again, not sure what's going on.  We will be trying other things such as
adding a second ground rod outside the shack instead of the single one we
use now.  We will also try isolating the amp some more and replacing the
coax feed line with hard line.  Thank you very much.  We will be contacting
Wacom directly tomorrow.
 
Rich Kelly, W2RRK

 x


 
> To: Repeater-Builder@yahoogroups.com
> From: wb6...@verizon.net
> Date: Wed, 8 Sep 2010 18:10:44 -0700
> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
> I'm not surprised- you're asking too much of a duplexer that has four 5"
> cans. According to my CommShop program, a duplexer with an 80 dB spec is
> more suitable with transmitter power in the 10-15 watt range, assuming a
> solid-state PA and a receiver sensitivity around 0.35 uV at 12 dB SINAD.
On
> a 100 watt repeater, I'd expect something like a WP-642, which has six 8"
> cans. BTDT, got the T-shirt and mug...
> 
> 73, Eric Lemmon WB6FLY
> 
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of RichardK
> Sent: Wednesday, September 08, 2010 3:11 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
> 
> 
> Good evening, our club has a Wacom WP-639 four can duplexer as part of our
> repeater system. Input Fq is 147.915 and Output Fq is 147.315. We have a
> 600kHz (+) offset. Very simply, our main problem is when we run the
> transmitter at full power 100 watts, there is a HUGE desense on the
receive
> side of things. When we drop the transmitter power level to around 20-50
> watts, the receive side opens WAY up to a large area where people can get
> into the repeater. As we begin to bring up the transmitter power, "white
> noise" begins to appear and the receive side starts to desense again. All
> the cables have been switched to double sheilded cables and all the same
> wavelength in length. We have the duplexer seperated & sheilded from the
> transmitter & preamp parts. We have not replaced the antenna feed coax
with
> double sheilded coax yet. Antenna is a Hustler G7 atop a 55' mast. The
> duplexer was retuned just over 1 year ago. Any suggestions as to what we
> could look into next? Some of us believe the problem is with the tuning of
> the duplexer receive cans. Thank you very much.
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Ken Arck]

At 06:18 PM 9/8/2010, Richard Kelly wrote:
>
>
>  We will be trying other things such as adding a second ground rod 
> outside the shack instead of the single one we use now.  We will 
> also try isolating the amp some more and replacing the coax feed 
> line with hard line.


<--That is a complete waste of time as that is not the problem. Your 
duplexer simply cannot provide enough isolation for the power level 
you're trying to run.

More grounding and replacing coax with hardline (unless your coax 
isn't doubleshield to start with) will buy you nothing.

Ken

--
President and CTO - Arcom Communications
Makers of repeater controllers and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net
"We don't just make 'em. We use 'em!"

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Richard Kelly]

Good evening Eric,
 
Maybe this is why when the trasmit power is dropped to the 20-50 watt range, 
the receive opens way up like it should.  However, according to the spec sheets 
regarding the Wacom SP-639 Duplexer, it is rated for 200 watts.  So, again, not 
sure what's going on.  We will be trying other things such as adding a second 
ground rod outside the shack instead of the single one we use now.  We will 
also try isolating the amp some more and replacing the coax feed line with hard 
line.  Thank you very much.  We will be contacting Wacom directly tomorrow.
 
Rich Kelly, W2RRK

 x


 
> To: Repeater-Builder@yahoogroups.com
> From: wb6...@verizon.net
> Date: Wed, 8 Sep 2010 18:10:44 -0700
> Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
> I'm not surprised- you're asking too much of a duplexer that has four 5"
> cans. According to my CommShop program, a duplexer with an 80 dB spec is
> more suitable with transmitter power in the 10-15 watt range, assuming a
> solid-state PA and a receiver sensitivity around 0.35 uV at 12 dB SINAD. On
> a 100 watt repeater, I'd expect something like a WP-642, which has six 8"
> cans. BTDT, got the T-shirt and mug...
> 
> 73, Eric Lemmon WB6FLY
> 
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of RichardK
> Sent: Wednesday, September 08, 2010 3:11 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Wacom WP-639 Duplexer question
> 
> 
> 
> Good evening, our club has a Wacom WP-639 four can duplexer as part of our
> repeater system. Input Fq is 147.915 and Output Fq is 147.315. We have a
> 600kHz (+) offset. Very simply, our main problem is when we run the
> transmitter at full power 100 watts, there is a HUGE desense on the receive
> side of things. When we drop the transmitter power level to around 20-50
> watts, the receive side opens WAY up to a large area where people can get
> into the repeater. As we begin to bring up the transmitter power, "white
> noise" begins to appear and the receive side starts to desense again. All
> the cables have been switched to double sheilded cables and all the same
> wavelength in length. We have the duplexer seperated & sheilded from the
> transmitter & preamp parts. We have not replaced the antenna feed coax with
> double sheilded coax yet. Antenna is a Hustler G7 atop a 55' mast. The
> duplexer was retuned just over 1 year ago. Any suggestions as to what we
> could look into next? Some of us believe the problem is with the tuning of
> the duplexer receive cans. Thank you very much.
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
  

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Eric Lemmon]

I'm not surprised- you're asking too much of a duplexer that has four 5"
cans.  According to my CommShop program, a duplexer with an 80 dB spec is
more suitable with transmitter power in the 10-15 watt range, assuming a
solid-state PA and a receiver sensitivity around 0.35 uV at 12 dB SINAD.  On
a 100 watt repeater, I'd expect something like a WP-642, which has six 8"
cans.  BTDT, got the T-shirt and mug...

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of RichardK
Sent: Wednesday, September 08, 2010 3:11 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Wacom WP-639 Duplexer question

  

Good evening, our club has a Wacom WP-639 four can duplexer as part of our
repeater system. Input Fq is 147.915 and Output Fq is 147.315. We have a
600kHz (+) offset. Very simply, our main problem is when we run the
transmitter at full power 100 watts, there is a HUGE desense on the receive
side of things. When we drop the transmitter power level to around 20-50
watts, the receive side opens WAY up to a large area where people can get
into the repeater. As we begin to bring up the transmitter power, "white
noise" begins to appear and the receive side starts to desense again. All
the cables have been switched to double sheilded cables and all the same
wavelength in length. We have the duplexer seperated & sheilded from the
transmitter & preamp parts. We have not replaced the antenna feed coax with
double sheilded coax yet. Antenna is a Hustler G7 atop a 55' mast. The
duplexer was retuned just over 1 year ago. Any suggestions as to what we
could look into next? Some of us believe the problem is with the tuning of
the duplexer receive cans. Thank you very much.

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[Kevin Custer]

  On 9/8/2010 6:11 PM, RichardK wrote:
> Good evening, our club has a Wacom WP-639 four can duplexer as part of our 
> repeater system.  Input Fq is 147.915 and Output Fq is 147.315.  We have a 
> 600kHz (+) offset.  Very simply, our main problem is when we run the 
> transmitter at full power 100 watts, there is a HUGE desense on the receive 
> side of things.  When we drop the transmitter power level to around 20-50 
> watts, the receive side opens WAY up to a large area where people can get 
> into the repeater.  As we begin to bring up the transmitter power, "white 
> noise" begins to appear and the receive side starts to desense again.  All 
> the cables have been switched to double sheilded cables and all the same 
> wavelength in length.  We have the duplexer seperated&  sheilded from the 
> transmitter&  preamp parts.  We have not replaced the antenna feed coax with 
> double sheilded coax yet.  Antenna is a Hustler G7 atop a 55' mast.  The 
> duplexer was retuned just over 1 year ago. Any suggestions as to what we 
> could look into next?  Some of us believe the problem is with the tuning of 
> the duplexer receive cans.  Thank you very much.


The Wacom WP-639 is insufficient for 100 solid state watts, unless you 
run a GE MASTR II PLL exciter and no preamp.

You will either need to replace the duplexer with another unit capable 
of properly isolating 100 solid state watts, add additional filters, 
change to a less noisy transmitter and amplifier (tubes are better - no 
I'm not kidding).

Kevin Custer - W3KKC

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Richard Kelly]

 i'm at work right now--I will get that info tomorrow!!
 
Rich K
W2RRK

 x


 


To: Repeater-Builder@yahoogroups.com
From: aseyb...@andrewseybold.com
Date: Wed, 8 Sep 2010 16:38:49 -0700
Subject: RE: [Repeater-Builder] Wacom WP-639 Duplexer question












What repeater are you running? Is it a GE Mastr II by chance?
 
Andy
 


From: Repeater-Builder@yahoogroups.com 
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of RichardK
Sent: Wednesday, September 08, 2010 3:11 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Wacom WP-639 Duplexer question
 
  



Good evening, our club has a Wacom WP-639 four can duplexer as part of our 
repeater system. Input Fq is 147.915 and Output Fq is 147.315. We have a 600kHz 
(+) offset. Very simply, our main problem is when we run the transmitter at 
full power 100 watts, there is a HUGE desense on the receive side of things. 
When we drop the transmitter power level to around 20-50 watts, the receive 
side opens WAY up to a large area where people can get into the repeater. As we 
begin to bring up the transmitter power, "white noise" begins to appear and the 
receive side starts to desense again. All the cables have been switched to 
double sheilded cables and all the same wavelength in length. We have the 
duplexer seperated & sheilded from the transmitter & preamp parts. We have not 
replaced the antenna feed coax with double sheilded coax yet. Antenna is a 
Hustler G7 atop a 55' mast. The duplexer was retuned just over 1 year ago. Any 
suggestions as to what we could look into next? Some of us believe the problem 
is with the tuning of the duplexer receive cans. Thank you very much.




  

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Ken Arck]

At 04:38 PM 9/8/2010, Andrew Seybold wrote:
>
>
>What repeater are you running? Is it a GE Mastr II by chance?
>
>


<---You hinting at the issue of Mastr II amp going spurious when the 
power is turned down too far?

Ken

--
President and CTO - Arcom Communications
Makers of repeater controllers and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net
"We don't just make 'em. We use 'em!"

Re: [Repeater-Builder] Wacom WP-639 Duplexer question

[Ken Arck]

At 03:11 PM 9/8/2010, RichardK wrote:
>
>
>Good evening, our club has a Wacom WP-639 four can duplexer as part 
>of our repeater system. Input Fq is 147.915 and Output Fq is 
>147.315. We have a 600kHz (+) offset. Very simply, our main problem 
>is when we run the transmitter at full power 100 watts, there is a 
>HUGE desense on the receive side of things. When we drop the 
>transmitter power level to around 20-50 watts, the receive side 
>opens WAY up to a large area where people can get into the repeater. 
>As we begin to bring up the transmitter power, "white noise" begins 
>to appear and the receive side starts to desense again. All the 
>cables have been switched to double sheilded cables and all the same 
>wavelength in length. We have the duplexer seperated & sheilded from 
>the transmitter & preamp parts. We have not replaced the antenna 
>feed coax with double sheilded coax yet. Antenna is a Hustler G7 
>atop a 55' mast. The duplexer was retuned just over 1 year ago. Any 
>suggestions as to what we could look into next? Some of us believe 
>the problem is with the tuning of the duplexer receive cans. Thank 
>you very much.

<---The WP-639 is spec'd at only 80 db of isolation @ a 600 kHz 
split. At 100 watts, that simply isn't enough to prevent desense. You 
need more isolation

Ken
--
President and CTO - Arcom Communications
Makers of repeater controllers and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net
"We don't just make 'em. We use 'em!"

RE: [Repeater-Builder] Wacom WP-639 Duplexer question

[Andrew Seybold]

What repeater are you running? Is it a GE Mastr II by chance?

 

Andy

 

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of RichardK
Sent: Wednesday, September 08, 2010 3:11 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Wacom WP-639 Duplexer question

 

  

Good evening, our club has a Wacom WP-639 four can duplexer as part of
our repeater system. Input Fq is 147.915 and Output Fq is 147.315. We
have a 600kHz (+) offset. Very simply, our main problem is when we run
the transmitter at full power 100 watts, there is a HUGE desense on the
receive side of things. When we drop the transmitter power level to
around 20-50 watts, the receive side opens WAY up to a large area where
people can get into the repeater. As we begin to bring up the
transmitter power, "white noise" begins to appear and the receive side
starts to desense again. All the cables have been switched to double
sheilded cables and all the same wavelength in length. We have the
duplexer seperated & sheilded from the transmitter & preamp parts. We
have not replaced the antenna feed coax with double sheilded coax yet.
Antenna is a Hustler G7 atop a 55' mast. The duplexer was retuned just
over 1 year ago. Any suggestions as to what we could look into next?
Some of us believe the problem is with the tuning of the duplexer
receive cans. Thank you very much.