RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Barry]

I expect wiki will answer it better than I but the amps are not linear so do 
not increase signals at a flat rate . 
To: Repeater-Builder@yahoogroups.com
From: lar...@hotmail.com
Date: Fri, 6 Feb 2009 05:16:17 +
Subject: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced 
Research Preamp





















--- In Repeater-Builder@yahoogroups.com, Barry  wrote:

>

> 

> What he is saying is , a lower gain preamp aplifies less noise in

relation to the signal so the audio sounds better 

> 



Not trying to be superpicky here, but this is something I need to

understand better...  Why, and how, would the lower-gain preamp

amplify less noise than signal?  Would the preamp not amplify anything

presented to it's input that is within it's operating parameters an

equal amount?



Laryn K8TVZ 




 

  



   
  












_
Get rid of those unwanted christmas presents! Get what you want at ebay. 
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Frover%2Eebay%2Ecom%2Frover%2F1%2F705%2D10129%2D5668%2D323%2F4%3Fid%3D10&_t=763807330&_r=hotmailTAGLINES&_m=EXT

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Camilo So]

Here is a true Hamtronics Helical Resonator preamp for 220 MHZ and 440 MHZ 
http://www.hamtronics.com/pdf/Manuals/HRA.pdf.

73
W4CSO


  - Original Message - 
  From: Barry 
  To: repeater-builder@yahoogroups.com 
  Sent: Thursday, February 05, 2009 11:52 PM
  Subject: RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or 
Advanced Research Preamp


  What he is saying is , a lower gain preamp aplifies less noise in relation to 
the signal so the audio sounds better 



--
  To: Repeater-Builder@yahoogroups.com
  From: lar...@hotmail.com
  Date: Fri, 6 Feb 2009 04:47:11 +
  Subject: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or 
Advanced Research Preamp


  --- In Repeater-Builder@yahoogroups.com, "Joe Burkleo"
   wrote:
  If for example the site has
  > a higher than normal noise floor a lower gain preamp will often times
  > amplify more of the signal and less of the extra site noise, where a
  > higher gain preamp may amplify both the noise and signal, giving you a
  > signal with more noise than you would like.

  Joe, scratchin' my head here... Would you be able to clarify the
  above statement for me?

  Laryn K8TVZ





--
  Get what you want at ebay. Get rid of those unwanted christmas presents! 

  

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Laryn Lohman]

--- In Repeater-Builder@yahoogroups.com, Barry  wrote:
>
> 
> What he is saying is , a lower gain preamp aplifies less noise in
relation to the signal so the audio sounds better 
> 

Not trying to be superpicky here, but this is something I need to
understand better...  Why, and how, would the lower-gain preamp
amplify less noise than signal?  Would the preamp not amplify anything
presented to it's input that is within it's operating parameters an
equal amount?

Laryn K8TVZ 

Re: [Repeater-Builder] Anyone Modified a Zetron 48B?

[Ken Arck]

The RAD should be in the receiver audio path not the transmitter path

Ken

At 07:16 PM 2/5/2009, ran...@farmtel.net wrote:


I am using a Zetron Model 48B as a repeater controller. Everything is
going fine except my addition of a Arcom RAD audio delay board. The
board is working great except now the CWID and status tones are not
transmitted.

The RAD is tied to the COS coming from the receiver to act as a gate to
eliminate squelch tails...works great! The RAD is inserted
between the tx audio coming out of the panel and the input to the
transmitter.

My problem is now the CWID and any audible status tones are not
transmitted because they are gated by the RAD since the COS is not active.

I am now trying to determine where inside the 48B I can gate the
transmitted audio ahead of the CWID and status tones generated by the panel.

Anyone here know where to find such a location inside a 48B?

Randy
WB0VHB



--
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!"

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Bob Ricci]

Maybe a bit of both. The antennas are side by side. I am more than 
familiar with diversity from my audio engineering days. I'll put the 
antennas on a switch and try this and that. I suspect that a 6dB gain 
antenna will yield the best all around performance. But then again 
maybe just a 3dB stick. The 9dB stick will do great across the ridge, 
but not well down into the canyons where the HT's will be. Only 
experimenting will tell for sure. I'm waiting for the controller to 
arrive so that I can assemble the final pieces. That's all that is 
holding up further tests. It is snowing quite nicely, but the 
antennas are already up.

--- In Repeater-Builder@yahoogroups.com, "Laryn Lohman"  
wrote:
>
> --- In Repeater-Builder@yahoogroups.com, "Bob Ricci"  wrote:
> 
>  Using three separate radios at the same 
> > location and "manual voting" we can hear that at one moment unity 
> > gain is better, while at another one of the other antennas is 
better. 
> 
> 
> Bob, are/were you using three radios connected to the three
> different-gain antennas and listening to the radios simultaneously? 
> If so, you have run into "diversity".  The changes/differences in
> signal level in each receiver were not necessarily caused only by 
the
> antenna gain.  They were caused by the very fact that the antennas 
are
> physically in different locations.
> 
> Laryn K8TVZ
>

Re: [Repeater-Builder] tracking receiver front end filters

[no6b]

At 2/5/2009 17:35, you wrote:

>Fixed tuned helical front ends as found in many of the
>GE and Motorhead Radios (and repeaters) are often a few
>MHz wide.

The measured 3 dB BW of the VHF HB GE MVP is 2 MHz.  40 dB BW is 5.7 
MHz.  Passband insertion loss is 5 to 6 dB.  The Mastr II & Exec II 
front-ends are identical in construction so I'd expect similar performance 
from those RXs.

Bob NO6B

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Laryn Lohman]

--- In Repeater-Builder@yahoogroups.com, "Bob Ricci"  wrote:

 Using three separate radios at the same 
> location and "manual voting" we can hear that at one moment unity 
> gain is better, while at another one of the other antennas is better. 


Bob, are/were you using three radios connected to the three
different-gain antennas and listening to the radios simultaneously? 
If so, you have run into "diversity".  The changes/differences in
signal level in each receiver were not necessarily caused only by the
antenna gain.  They were caused by the very fact that the antennas are
physically in different locations.

Laryn K8TVZ

RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Barry]

What he is saying is , a lower gain preamp aplifies less noise in relation to 
the signal so the audio sounds better 

To: Repeater-Builder@yahoogroups.com
From: lar...@hotmail.com
Date: Fri, 6 Feb 2009 04:47:11 +
Subject: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced 
Research Preamp





















--- In Repeater-Builder@yahoogroups.com, "Joe Burkleo"

 wrote:

 If for example the site has

> a higher than normal noise floor a lower gain preamp will often times

> amplify more of the signal and less of the extra site noise, where a

> higher gain preamp may amplify both the noise and signal, giving you a

> signal with more noise than you would like.



Joe, scratchin' my head here...  Would you be able to clarify the

above statement for me?



Laryn K8TVZ




 

  



   
  












_
Get rid of those unwanted christmas presents! Get what you want at ebay. 
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Frover%2Eebay%2Ecom%2Frover%2F1%2F705%2D10129%2D5668%2D323%2F4%3Fid%3D10&_t=763807330&_r=hotmailTAGLINES&_m=EXT

RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[no6b]

At 2/5/2009 15:03, you wrote:
>With that short of a run I would be more concerned with the repeater being
>in the near field of the antenna.
>
>-Kevin

I've read other similar comments.  Guess I've been lucky: the last 2 meter 
system I set up has the antenna barely 15 ft directly above the 
repeater.  No desense.  The antenna is almost directly above the repeater 
so that may help.

Bob NO6B

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Laryn Lohman]

--- In Repeater-Builder@yahoogroups.com, "Joe Burkleo"
 wrote:
 If for example the site has
> a higher than normal noise floor a lower gain preamp will often times
> amplify more of the signal and less of the extra site noise, where a
> higher gain preamp may amplify both the noise and signal, giving you a
> signal with more noise than you would like.


Joe, scratchin' my head here...  Would you be able to clarify the
above statement for me?

Laryn K8TVZ

Re: [Repeater-Builder] Off Topic

[Chris Carruba]

Try using a boot loader that can boot more than one operating system, such as 
NTLDR, LILO, or GRUB.
 Best Regards,

Chris Carruba (WQIK389)

CompuTec Data Systems
Custom Written Software, 
Networking, Forensic Data Recovery







From: John 
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, February 5, 2009 3:40:52 PM
Subject: Re: [Repeater-Builder] Off Topic


MCH wrote:

>Dual boot is the only way I know of...
>

What's the best way to do a dual boot?

John


   


  

Re: [Repeater-Builder] CD IDer needed for GR300

[Brian]

Joe

You can buy a basic repeater controller for (The Basic) $83.95 and it 
has many features including
a pending ID timer, a polite ID timer and a bunch more. It all programs 
with DTMF.

www.ics-ctrl.com
Brian
ka9pmm


Joe Serocki wrote:
>
> I have a GR300 with M120/M10 radios. Seems nice, puts out about 25 
> watts, clean.
>
> I need to get an IDer into this repeater. Suggestions on how and where 
> to get it?
>
> Thanks
>
> *73*
>
> * *
>
> *Joe Serocki, N9IFG*
>
> *Prez, WeLCARS (www.welcars.org )*
>
> * *
>
> *Commander Peter Quincy Taggart: Never give up, never surrender!*
>
> *Red Green: Quando omni flunkus moritati - when all else fails, play 
> dead.*
>
> *Riley Hollingsworth: If you don't like it spin the dial!*
>
> *Serocki: It’s better to ask for forgiveness than permission, but you 
> better have whatever it is fixed first!*
>
> * *
>
>  








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[Repeater-Builder] Anyone Modified a Zetron 48B?

[rande1]

I am using a Zetron Model 48B as a repeater controller.  Everything is 
going fine except my addition of a Arcom RAD audio delay board.  The 
board is working great except now the CWID and status tones are not 
transmitted.

The RAD is tied to the COS coming from the receiver to act as a gate to 
eliminate squelch tails...works great!  The RAD is inserted 
between the tx audio coming out of the panel and the input to the 
transmitter.

My problem is now the CWID and any audible status tones are not 
transmitted because they are gated by the RAD since the COS is not active. 

I am now trying to determine where inside the 48B I can gate the 
transmitted audio ahead of the CWID and status tones generated by the panel.

Anyone here know where to find such a location inside a 48B? 

Randy
WB0VHB

[Repeater-Builder] tracking receiver front end filters

[skipp025]

> ANYTHING with a software tuned front end is considered 
> broad when talking about hi-level rf site performance. 

I wouldn't say "anything"... many receiver front-end filter 
sections are designed to electronically adjust and optimize... 
aka a "tracking receiver pre-selector front end". I have 
seen some pretty neat'o tracking receiver filter sections 
with impressive performance values 

> That is why helical resonator front ends are desirable.

The helical front end receivers are no free lunch deal. 

Fixed tuned helical front ends as found in many of the 
GE and Motorhead Radios (and repeaters) are often a few 
MHz wide.  

The previously mentioned Toko Brand helicals are even 
wider (lower Q, less number of sections, great taste, 
less filling) than the typical GE, Motorhead assemblies 
we find in front of our favorite surplus commercial 
receiver. 

While a few MHz band-width might be OK in many classic 
base and repeater station applications... persons trusting 
helical filters with pre-amplifiers in/at really busy 
close spaced ("on the margins") situations are often in 
for a surprise visit from Mr. Gremlins N Grunge. 

There is smart information, engineering and application 
information available on the web... to make a really 
high performance "smokin" repeater receiver system. I've 
just not found it all in one place yet. 

cheers, 
s. 

Re: [Repeater-Builder] Re: request for info; "DV-200, Palomar Telecom"

[WA7ZZT]

The  DV-200 is a voice storage board made by Palomar Telecom, Inc. 
around 1992
They are no longer in business.
The DV-200, DV-64 and VS-100 were all Natural voice play back boards.
They were programmed using  the opitional SDS-1000 speach development 
system.

Dennis

web_magician wrote:
>
> --- In Repeater-Builder@yahoogroups.com 
> , "kb4mdz"  
> wrote on
> Thu Feb 5, 2009 at 2:40 pm:
> >
> >
> > Graced with a Palomar Telecom DV-200 board; apparently it's a voice
> > storage board, but I have no docs; I guess Palomar Telecom went out
> of
> > business sometime after 1992.
> >
> > Anyone have a half a clue on this unit?
> >
> > Thanks
> > Chuk Gleason
> > Cary, NC
>
> If you still have it I'd be interested in playing with it.
>
> Mike WA6ILQ
> co-web-master at www.repeate-builder.com
>
>
>   

Re: [Repeater-Builder] Vertex VXR 5000

[Maire-Radios]

need the new ver. of the cable  the old one does not work with it.


  - Original Message - 
  From: Joe 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Thursday, February 05, 2009 2:10 PM
  Subject: [Repeater-Builder] Vertex VXR 5000


  Does anyone know where I can find a VPl-1 programming cable? Seen some 
  on Ebay but they are listed as not working with the VXR-7000, are the 
  pinouts differant from the mobile ham radios to the repeater the VPL-1 
  is supposed to work with? 

  Purchased a UHF repeater to run on Echolink, planning on the 
  Tigertronics Signalink USB interface. Has anyone used the Signalink 
  with success? 

  Can I run IRLP off the same Signalink or is a seperate interface 
  required? 

  Thx,

  Joe


  

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[Bob Ricci]

Thank you for the advice. This is why I was going to go to a sielded 
barrier strip so that I could easily wire separate connections and 
add feed-through caps if needed. But nonetheless, I'll learn by 
making mistakes and making adjustments.

Go easy on me, Lads, This is my first go at this. Remember your first 
repeater? One would hope that as Elmer's one could help someone out 
without making them feel stupid for asking. I'm sure that it isn't 
deliberate...

Why a preamp? Please read backwards. The primary users will be using 
hand-helds -- low power and rubber duckies -- throught a mountainous 
region. If it turns out that a preamp is not needed, great! One less 
expense. I am certain that the choice of antennas will prove more 
important than a preamp. Besides, a preamp after a duplexer cannot 
amplify a signal that is no longer there.

Baby steps. Outside work is now on hold as the snow begins to fall...

--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  
wrote:
>
> Why do you feel the need for a preamp?
> 
> Also, to check for desense, you need everything operational. Get 
someone 
> with a very weak signal to transmit while you disable the repeater 
> transmitter. If there is no change in noise on the repeater's local 
speaker, 
> you are OK. If the signal gets quieter, then you have desense.
> 
> Oh, and the transmit and receive audio lines to the controller 
should be 
> individually shielded, not just an overall shield around a bundle 
of wires.
> 
> Chuck
> WB2EDV
> 
> 
> 
> 
> - Original Message - 
> From: "Bob Ricci" 
> To: 
> Sent: Thursday, February 05, 2009 5:04 PM
> Subject: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp 
> orAdvanced Research Preamp
> 
> 
> > Thank you all for some excellent advice for a first-time repeater
> > builder. I have decided to move the antenna to the other side of 
the
> > house and push it up 60 feet. My home sits about ~15 feet below 
the
> > road, so this will give me a net gain of ~45 feet. I'll feed it 
with
> > hard line and do it right. This will get the repeater antenna away
> > from  my own stuff in the shack. The repeater will actually go 
into a
> > cinder block walled room
> >
> > The Vertex VX-4100's are solid radios encased in aluminum. The
> > plastic on the outside is decorative. Using the repeater right 
next
> > door to me and a hand-held without an antenna and 1/8th of a 
watt, I
> > generated a signal and then kerchunked the repeater next door. No
> > desense or white noise. I'll check this with a service monitor 
when
> > it gets back up here, but this test was positive and without the
> > cavities inline.
> >
> > I will use quality DB15 shielded computer cables to soldered 
DB9's on
> > the RC210 controller.
> >
>

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[Chuck Kelsey]

Why do you feel the need for a preamp?

Also, to check for desense, you need everything operational. Get someone 
with a very weak signal to transmit while you disable the repeater 
transmitter. If there is no change in noise on the repeater's local speaker, 
you are OK. If the signal gets quieter, then you have desense.

Oh, and the transmit and receive audio lines to the controller should be 
individually shielded, not just an overall shield around a bundle of wires.

Chuck
WB2EDV




- Original Message - 
From: "Bob Ricci" 
To: 
Sent: Thursday, February 05, 2009 5:04 PM
Subject: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp 
orAdvanced Research Preamp


> Thank you all for some excellent advice for a first-time repeater
> builder. I have decided to move the antenna to the other side of the
> house and push it up 60 feet. My home sits about ~15 feet below the
> road, so this will give me a net gain of ~45 feet. I'll feed it with
> hard line and do it right. This will get the repeater antenna away
> from  my own stuff in the shack. The repeater will actually go into a
> cinder block walled room
>
> The Vertex VX-4100's are solid radios encased in aluminum. The
> plastic on the outside is decorative. Using the repeater right next
> door to me and a hand-held without an antenna and 1/8th of a watt, I
> generated a signal and then kerchunked the repeater next door. No
> desense or white noise. I'll check this with a service monitor when
> it gets back up here, but this test was positive and without the
> cavities inline.
>
> I will use quality DB15 shielded computer cables to soldered DB9's on
> the RC210 controller.
>

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[JOHN MACKEY]

ANYTHING with a software tuned front end is considered broad when talking
about hi-level rf site performance.  That is why helical resonator front ends
are desirable.

-- Original Message --
Received: Thu, 05 Feb 2009 03:16:20 PM PST
From: "Bob Ricci" 
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced
Research Preamp

> "...the receiver in this application has a very broad frontend..."
> 
> Not quite. The radio is software tuned and aligned for the actual 
> frequency range in service. It is *capable* of the broad range of 134-
> 174. That is not to say that a preselector won't help an already 
> excellent receiver, but a Angle Linear has already been ordered.
> 
> --- In Repeater-Builder@yahoogroups.com, "motarolla_doctor" 
>  wrote:
> >
> > Very good, excellent points Eric. I might add that the receiver in
> > this application has a very broad frontend. You NEED a receiver
> > preselector for best performance.
> > 
> > "Eric Lemmon" ...> wrote:
> > > Rick,
> > > You made some very good points.  I can offer two comments:  For 
> > > hookups within the repeater cabinet, use RG-400/U coax instead of 
> > > RG-142/U.  RG-400 has a stranded center conductor, while RG-142 
> has
> > a solid steel center conductor that breaks easily when repeatedly 
> flexed.
> > > 
> > > Regarding the Vertex UHF repeaters, I corrected an in-cabinet 
> desense
> > > problem by replacing all three internal jumpers- which were 
> unmarked
> > > gray-jacketed single-shield cables- with double-shielded RG-400 
> cable.
> > > 
> > > 73, Eric Lemmon WB6FLY
> >
> 
> 
> 

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[Bob Ricci]

"...the receiver in this application has a very broad frontend..."

Not quite. The radio is software tuned and aligned for the actual 
frequency range in service. It is *capable* of the broad range of 134-
174. That is not to say that a preselector won't help an already 
excellent receiver, but a Angle Linear has already been ordered.

--- In Repeater-Builder@yahoogroups.com, "motarolla_doctor" 
 wrote:
>
> Very good, excellent points Eric. I might add that the receiver in
> this application has a very broad frontend. You NEED a receiver
> preselector for best performance.
> 
> "Eric Lemmon" ...> wrote:
> > Rick,
> > You made some very good points.  I can offer two comments:  For 
> > hookups within the repeater cabinet, use RG-400/U coax instead of 
> > RG-142/U.  RG-400 has a stranded center conductor, while RG-142 
has
> a solid steel center conductor that breaks easily when repeatedly 
flexed.
> > 
> > Regarding the Vertex UHF repeaters, I corrected an in-cabinet 
desense
> > problem by replacing all three internal jumpers- which were 
unmarked
> > gray-jacketed single-shield cables- with double-shielded RG-400 
cable.
> > 
> > 73, Eric Lemmon WB6FLY
>

RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Kevin King]

With that short of a run I would be more concerned with the repeater being
in the near field of the antenna. 

-Kevin

>  I am blessed with my location and yes, noise can be high. I'll
>try without the preamp first and see where I'm at, and the use of the
>proper antenna will help. I've spent so much alreqady that a few more
>buckis for 7/8" won't make a difference and will err on the side of
>caution with intermod.

Again, 20 ft. of 7/8" for 2 meters is an unnecessary expense.  20 ft. of 
RG-214 has only 0.5 dB of loss @ 146 MHz - quite acceptable for a 
first-rate system, and it won't cost you that much even if you have to buy 
it @ retail $$.

Bob NO6B







Yahoo! Groups Links

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[motarolla_doctor]

Very good, excellent points Eric. I might add that the receiver in
this application has a very broad frontend. You NEED a receiver
preselector for best performance.

"Eric Lemmon" ...> wrote:
> Rick,
> You made some very good points.  I can offer two comments:  For 
> hookups within the repeater cabinet, use RG-400/U coax instead of 
> RG-142/U.  RG-400 has a stranded center conductor, while RG-142 has
a solid steel center conductor that breaks easily when repeatedly flexed.
> 
> Regarding the Vertex UHF repeaters, I corrected an in-cabinet desense
> problem by replacing all three internal jumpers- which were unmarked
> gray-jacketed single-shield cables- with double-shielded RG-400 cable.
> 
> 73, Eric Lemmon WB6FLY

Re: [Repeater-Builder] Vertex VXR 5000

[DCFluX]

I did post a schematic that is compatable with the VXR-7000 on the
repeater builder site.

On Thu, Feb 5, 2009 at 12:10 PM, Joe  wrote:
> Does anyone know where I can find a VPl-1 programming cable? Seen some
> on Ebay but they are listed as not working with the VXR-7000, are the
> pinouts differant from the mobile ham radios to the repeater the VPL-1
> is supposed to work with?
>
> Purchased a UHF repeater to run on Echolink, planning on the
> Tigertronics Signalink USB interface. Has anyone used the Signalink
> with success?
>
> Can I run IRLP off the same Signalink or is a seperate interface
> required?
>
>  Thx,
>
>  Joe
>
>
>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>
>

[Repeater-Builder] Re: request for info; "DV-200, Palomar Telecom"

[web_magician]

--- In Repeater-Builder@yahoogroups.com, "kb4mdz"  wrote on 
Thu Feb 5, 2009 at 2:40 pm:
>
> 
> Graced with a Palomar Telecom DV-200 board; apparently it's a voice 
> storage board, but I have no docs; I guess Palomar Telecom went out 
of 
> business sometime after 1992.
> 
> Anyone have a half a clue on this unit?
> 
> Thanks
> Chuk Gleason
> Cary, NC

If you still have it I'd be interested in playing with it.

Mike WA6ILQ
co-web-master at www.repeate-builder.com 

[Repeater-Builder] Vertex VXR 5000

[Joe]

Does anyone know where I can find a VPl-1 programming cable? Seen some 
on Ebay but they are listed as not working with the VXR-7000, are the 
pinouts differant from the mobile ham radios to the repeater the VPL-1 
is supposed to work with? 

Purchased a UHF repeater to run on Echolink, planning on the 
Tigertronics Signalink USB interface. Has anyone used the Signalink 
with success? 

Can I run IRLP off the same Signalink or is a seperate interface 
required? 

 Thx,

 Joe

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[Bob Ricci]

Thank you all for some excellent advice for a first-time repeater 
builder. I have decided to move the antenna to the other side of the 
house and push it up 60 feet. My home sits about ~15 feet below the 
road, so this will give me a net gain of ~45 feet. I'll feed it with 
hard line and do it right. This will get the repeater antenna away 
from  my own stuff in the shack. The repeater will actually go into a 
cinder block walled room

The Vertex VX-4100's are solid radios encased in aluminum. The 
plastic on the outside is decorative. Using the repeater right next 
door to me and a hand-held without an antenna and 1/8th of a watt, I 
generated a signal and then kerchunked the repeater next door. No 
desense or white noise. I'll check this with a service monitor when 
it gets back up here, but this test was positive and without the 
cavities inline.

I will use quality DB15 shielded computer cables to soldered DB9's on 
the RC210 controller.

--- In Repeater-Builder@yahoogroups.com, "Eric Lemmon"  
wrote:
>
> Rick,
> 
> You made some very good points.  I can offer two comments:  For 
hookups
> within the repeater cabinet, use RG-400/U coax instead of RG-
142/U.  RG-400
> has a stranded center conductor, while RG-142 has a solid steel 
center
> conductor that breaks easily when repeatedly flexed.
> 
> Regarding the Vertex UHF repeaters, I corrected an in-cabinet 
desense
> problem by replacing all three internal jumpers- which were unmarked
> gray-jacketed single-shield cables- with double-shielded RG-400 
cable.
> 
> 73, Eric Lemmon WB6FLY
>  
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Rick Beatty
> Sent: Thursday, February 05, 2009 10:46 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] Re: Hamtronics Helical Resonator 
Preamp or
> Advanced Research Preamp
> 
> Hi All -- Here is my take on the preamp vs no preamp situation -- 
and with
> Vertex repeaters -- 
> 
> First -- Preamps are not the solution to most of our troubles, in 
fact it
> has been my experience over the years that they are more trouble 
than they
> are helpful
> I agree with Skipp and others when it is said to get rid of the LMR-
400 and
> replace it. For inside the box use 142b or 223, something with low 
loss but
> is manageable to use on the duplexer and interconnects. rg-214 is 
way over
> the top for most of this stuff. For antennas, don't use less than 
1/2
> heliax. Even '214 will get noisy if there is any flex or it is out 
in the
> weather a couple of seasons. 
> 
> No-Preamps, we as amateurs look a preamps as a panacea for many 
things,
> including the lack of perceived receiver sensitivity. But it is 
interesting
> to note a couple of things. One, a 0.4 uV receiver is as good as it 
is going
> to get, in most cases because of the fact you're setting in a high 
place and
> the MDS combined with the power out, 50 to 75 watts, is going to be 
about
> equal with a 4 pole antenna. Not rocket science, and you can 
actually run
> that test iif you're on a hill and have the proper equipment to do 
so.
> Secondly, preamps, even at 10 dB gain, really only add about 3 dB 
of signal
> and the rest is just moving the noise floor higher. And in some 
cases really
> create a need for more signal to open the repeater's receiver. If 
you're
> having issues with the receiver, it would be my recommendation to 
sit down
> and take a hard look at the equipment, duplexer, antenna, and 
cables. There
> are so many variables here in just those 4 items that it will take 
some time
> to optimize each of them to your needs. 
> 
> Coax, again I agree with all of those on here that LMR, 214, 213, 
RG-8 etc
> on a repeater is just not a good idea. Use hardline - 
> 
> Vertex, I have nothing bad to say about them other than my 
experience with 2
> UHF machines. Both of them exhibit the same characteristics so I 
will just
> speak in general terms. What I found was that there was/is a lot of
> crosstalk in the repeater box itself and even though the duplexer 
was well
> tuned we could not get the isolation down on the system as a whole. 
The
> second problem I found was that the LO runs all the time! This not 
good; it
> interferes with others on the site and can cause strange mixes 
within the
> box that could desense your receiver, especially if there is a 
signal within
> the IF of the repeater, either high or low. 
> 
> How did we fix it? We went to a GE box, LOL! 
> 
> So, I guess in conclusion here, before spending your hard earned 
dollars,
> for preamps, helical resonators, and the like take good gander at 
the
> situation and try to break it down to a common denominator, with a 
clear
> picture as to what you're seeing. Do all of the things necessary 
for good
> repeater operation and then look again. I'll bet you just haven't 
found the
> right place to look yet. 
> 
> rick NU7Z
>  
> 
> 
> On Thu, Feb 5, 2009 at 10:18 AM, skipp025  

RE: [Repeater-Builder] Syntors at the salvage yard. Drive level to the 45 watt VHF PA?

[Eric Lemmon]

Skipp,

Your VHF Syntor is the 40 watt model.  The 2511 transistor at Q802 was used
only in the HLD4125A power amplifier.  According to the Syntor manual
6881043E40 (still available for about $21), the variable-output exciter
supplies 1.5 watts maximum drive to the PA.  Some components in the PA were
range-specific; Range II is 146-150.8 MHz, Range III is 150.8-162 MHz, and
Range IV is 162-174 MHz.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of skipp025
Sent: Thursday, February 05, 2009 10:52 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Syntors at the salvage yard. Drive level to the
45 watt VHF PA?

Re: Syntors at the salvage yard. 

Drive level to the 45 watt VHF PA? 

 

Yesterday we made it over to a longtime friend's Government 
Surplus Buyer/Seller/Dealer location/warehouse. He's got a 
great deal on LaMarche rack mount battery chargers if anyone 
is seriously looking for one. 

In one portion of his facility/building... he scrapped a 
fair number of VHF Syntor mobiles for the estimated weight 
value of the aluminum heat sink (metal). A truly sad day 
for surplus Motorola Syntor radios ... 

All the circuit boards were removed and sitting in pile so 
I picked up and purchased (cheap) a fair number of the 45 
watt RF PA PC-Boards (still in darn good shape). 

So... can anyone quickly tell me the drive level? 

Board has two transistor stages 
driver M9860 
final M2511 
reported output power rating 45 watt. 

thanks 
skipp 
skipp025 at yahoo.com 

Re: [Repeater-Builder] Off Topic

[MCH]

I used a program called (I think) Boot Camp.

Joe M.

John wrote:
> MCH wrote:
> 
>> Dual boot is the only way I know of...
>>
> 
> What's the best way to do a dual boot?
> 
> John
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 

Re: [Repeater-Builder] Off Topic

[John]

MCH wrote:

>Dual boot is the only way I know of...
>

What's the best way to do a dual boot?

John

Re: [Repeater-Builder] Syntors at the salvage yard. Drive level to the 45 watt VHF PA?

[Kris Kirby]

On Thu, 5 Feb 2009, skipp025 wrote:
> So...  can anyone quickly tell me the drive level?

IIRC, it's somewhere between 200 mW and 1.125W. +33dBm I think. The last 
stage of the exciter sets the power out for the radio, just like the 
Mitrek. A 45W PA can be turned down to 25W to run for the end of days.

--
Kris Kirby, KE4AHR  
But remember, with no superpowers comes no responsibility. 
--rly

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[Rick Beatty]

Hi Eric and the Group -- Thanks for your comments and yes, Rg-400u is a good
substitute as well. I completely forgot about that one -- old age I guess
LOL!

73 - Rick NU7Z

On Thu, Feb 5, 2009 at 11:05 AM, Eric Lemmon  wrote:

>   Rick,
>
> You made some very good points. I can offer two comments: For hookups
> within the repeater cabinet, use RG-400/U coax instead of RG-142/U. RG-400
> has a stranded center conductor, while RG-142 has a solid steel center
> conductor that breaks easily when repeatedly flexed.
>
> Regarding the Vertex UHF repeaters, I corrected an in-cabinet desense
> problem by replacing all three internal jumpers- which were unmarked
> gray-jacketed single-shield cables- with double-shielded RG-400 cable.
>
> 73, Eric Lemmon WB6FLY
>
>
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:Repeater-Builder@yahoogroups.com]
> On Behalf Of Rick Beatty
> Sent: Thursday, February 05, 2009 10:46 AM
> To: Repeater-Builder@yahoogroups.com 
> Subject: Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or
> Advanced Research Preamp
>
> Hi All -- Here is my take on the preamp vs no preamp situation -- and with
> Vertex repeaters --
>
> First -- Preamps are not the solution to most of our troubles, in fact it
> has been my experience over the years that they are more trouble than they
> are helpful
> I agree with Skipp and others when it is said to get rid of the LMR-400 and
> replace it. For inside the box use 142b or 223, something with low loss but
> is manageable to use on the duplexer and interconnects. rg-214 is way over
> the top for most of this stuff. For antennas, don't use less than 1/2
> heliax. Even '214 will get noisy if there is any flex or it is out in the
> weather a couple of seasons.
>
> No-Preamps, we as amateurs look a preamps as a panacea for many things,
> including the lack of perceived receiver sensitivity. But it is interesting
> to note a couple of things. One, a 0.4 uV receiver is as good as it is
> going
> to get, in most cases because of the fact you're setting in a high place
> and
> the MDS combined with the power out, 50 to 75 watts, is going to be about
> equal with a 4 pole antenna. Not rocket science, and you can actually run
> that test iif you're on a hill and have the proper equipment to do so.
> Secondly, preamps, even at 10 dB gain, really only add about 3 dB of signal
> and the rest is just moving the noise floor higher. And in some cases
> really
> create a need for more signal to open the repeater's receiver. If you're
> having issues with the receiver, it would be my recommendation to sit down
> and take a hard look at the equipment, duplexer, antenna, and cables. There
> are so many variables here in just those 4 items that it will take some
> time
> to optimize each of them to your needs.
>
> Coax, again I agree with all of those on here that LMR, 214, 213, RG-8 etc
> on a repeater is just not a good idea. Use hardline -
>
> Vertex, I have nothing bad to say about them other than my experience with
> 2
> UHF machines. Both of them exhibit the same characteristics so I will just
> speak in general terms. What I found was that there was/is a lot of
> crosstalk in the repeater box itself and even though the duplexer was well
> tuned we could not get the isolation down on the system as a whole. The
> second problem I found was that the LO runs all the time! This not good; it
> interferes with others on the site and can cause strange mixes within the
> box that could desense your receiver, especially if there is a signal
> within
> the IF of the repeater, either high or low.
>
> How did we fix it? We went to a GE box, LOL!
>
> So, I guess in conclusion here, before spending your hard earned dollars,
> for preamps, helical resonators, and the like take good gander at the
> situation and try to break it down to a common denominator, with a clear
> picture as to what you're seeing. Do all of the things necessary for good
> repeater operation and then look again. I'll bet you just haven't found the
> right place to look yet.
>
> rick NU7Z
>
>
> On Thu, Feb 5, 2009 at 10:18 AM, skipp025 
> 
>  > wrote:
>
> Hi Ralph,
>
> > Ralph  wrote:
> > I have never seen or used a Hamtronics preamp. I don't
> > know anything about their specs or how truthful they
> > are. Maybe some one out there in the great bits might
> > have an answer. Skipp? Eric? anyone??
>
> I'll answer up to the anyone label...
>
> Through the years Hamtronics has offered up a number of
> quite different RF Preamplifier kits and assembled boards.
>
> Relative to the industry they are truthful and their
> products are a good dollar value. Even more valuable is
> the experience and knowledge many people receive for
> constructing and setting up their kits.
>
> The RF Preamplifier you're probably talking about is not
> a true helical filter design. Hamtronics no longer offers
> the HRA series with the on board Toko (brand) helical
> filter.

RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp orAdvanced Research Preamp

[Eric Lemmon]

Rick,

You made some very good points.  I can offer two comments:  For hookups
within the repeater cabinet, use RG-400/U coax instead of RG-142/U.  RG-400
has a stranded center conductor, while RG-142 has a solid steel center
conductor that breaks easily when repeatedly flexed.

Regarding the Vertex UHF repeaters, I corrected an in-cabinet desense
problem by replacing all three internal jumpers- which were unmarked
gray-jacketed single-shield cables- with double-shielded RG-400 cable.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Rick Beatty
Sent: Thursday, February 05, 2009 10:46 AM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or
Advanced Research Preamp

Hi All -- Here is my take on the preamp vs no preamp situation -- and with
Vertex repeaters -- 

First -- Preamps are not the solution to most of our troubles, in fact it
has been my experience over the years that they are more trouble than they
are helpful
I agree with Skipp and others when it is said to get rid of the LMR-400 and
replace it. For inside the box use 142b or 223, something with low loss but
is manageable to use on the duplexer and interconnects. rg-214 is way over
the top for most of this stuff. For antennas, don't use less than 1/2
heliax. Even '214 will get noisy if there is any flex or it is out in the
weather a couple of seasons. 

No-Preamps, we as amateurs look a preamps as a panacea for many things,
including the lack of perceived receiver sensitivity. But it is interesting
to note a couple of things. One, a 0.4 uV receiver is as good as it is going
to get, in most cases because of the fact you're setting in a high place and
the MDS combined with the power out, 50 to 75 watts, is going to be about
equal with a 4 pole antenna. Not rocket science, and you can actually run
that test iif you're on a hill and have the proper equipment to do so.
Secondly, preamps, even at 10 dB gain, really only add about 3 dB of signal
and the rest is just moving the noise floor higher. And in some cases really
create a need for more signal to open the repeater's receiver. If you're
having issues with the receiver, it would be my recommendation to sit down
and take a hard look at the equipment, duplexer, antenna, and cables. There
are so many variables here in just those 4 items that it will take some time
to optimize each of them to your needs. 

Coax, again I agree with all of those on here that LMR, 214, 213, RG-8 etc
on a repeater is just not a good idea. Use hardline - 

Vertex, I have nothing bad to say about them other than my experience with 2
UHF machines. Both of them exhibit the same characteristics so I will just
speak in general terms. What I found was that there was/is a lot of
crosstalk in the repeater box itself and even though the duplexer was well
tuned we could not get the isolation down on the system as a whole. The
second problem I found was that the LO runs all the time! This not good; it
interferes with others on the site and can cause strange mixes within the
box that could desense your receiver, especially if there is a signal within
the IF of the repeater, either high or low. 

How did we fix it? We went to a GE box, LOL! 

So, I guess in conclusion here, before spending your hard earned dollars,
for preamps, helical resonators, and the like take good gander at the
situation and try to break it down to a common denominator, with a clear
picture as to what you're seeing. Do all of the things necessary for good
repeater operation and then look again. I'll bet you just haven't found the
right place to look yet. 

rick NU7Z
 


On Thu, Feb 5, 2009 at 10:18 AM, skipp025 mailto:skipp...@yahoo.com> > wrote:


Hi Ralph, 

> Ralph  wrote:
> I have never seen or used a Hamtronics preamp. I don't 
> know anything about their specs or how truthful they 
> are. Maybe some one out there in the great bits might 
> have an answer. Skipp? Eric? anyone?? 

I'll answer up to the anyone label... 

Through the years Hamtronics has offered up a number of 
quite different RF Preamplifier kits and assembled boards. 

Relative to the industry they are truthful and their 
products are a good dollar value. Even more valuable is 
the experience and knowledge many people receive for 
constructing and setting up their kits. 

The RF Preamplifier you're probably talking about is not 
a true helical filter design. Hamtronics no longer offers 
the HRA series with the on board Toko (brand) helical 
filter. Their current products (when I last looked) were 
broad-band and some with modest tuned circuits, which is 
not really a true helical layout.

After completing a recent very large vhf receive

Re: [Repeater-Builder] Help with Motorola amp

[Chuck Kelsey]

A photo of the entire PA may help someone identify it better. Looks like a 
resistor. If it's one of the resistors I'm thinking of, it might be cheaper to 
replace the entire board because the final transistors may be blown. But, it 
can't be certain without more information. And I'm not that much of a Motorola 
guy.

Chuck
WB2EDV



  - Original Message - 
  From: The Marlins 
  To: repeater-builder@yahoogroups.com 
  Sent: Thursday, February 05, 2009 12:30 PM
  Subject: [Repeater-Builder] Help with Motorola amp


  Hello group,
  The Fessenden Club on Hatteras Island has a Motorola "brick" mobile type amp 
on our Two Meter repeater.
  We have had this thing for years.  we feed it about 7 watts and it faithfully 
puts out about sixty into our Sinclair duplexer and up to a DB 224 at about 180 
ft.  This amp has crashed and one of our fellow club members is repairing it 
(AA3ID).But we cant find any information about it anywhere.
  HELP !   
   K4HAT down Cape Hatteras way.

  Amp is a Motorola N1254A, VHF
  Board is the main power amp board, 84E84361B01
  Unknown component is either a diode or resistor.

  Photos attached



   



  

RE: [Repeater-Builder] Help with Motorola amp

[Eric Lemmon]

It's not clear (literally) which component in the pictures is suspect.
However, the N1254A amplifier was never intended, nor is it suitable, for
repeater service.  It was designed as an accessory for the MX300
ConvertaCom, where its duty cycle was very low, and it was fed just 4 to 5
watts.  The fact that it lasted as long as it did is probably luck, and
possibly a testament to its good design.

The instruction manual for the N1254A amplifier is 6881013C30 which,
unfortunately, is NLA from Motorola.  There are a few of these amplifiers
and manuals listed on one of the auction sites.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of The Marlins
Sent: Thursday, February 05, 2009 9:31 AM
To: repeater-builder@yahoogroups.com
Subject: [Repeater-Builder] Help with Motorola amp

Hello group,
The Fessenden Club on Hatteras Island has a Motorola "brick" mobile type amp
on our Two Meter repeater.
We have had this thing for years.  we feed it about 7 watts and it
faithfully puts out about sixty into our Sinclair duplexer and up to a DB
224 at about 180 ft.  This amp has crashed and one of our fellow club
members is repairing it (AA3ID).But we cant find any information
about it anywhere.
HELP !   
 K4HAT down Cape Hatteras way.
 
Amp is a Motorola N1254A, VHF
Board is the main power amp board, 84E84361B01
Unknown component is either a diode or resistor.
 
Photos attached

[Repeater-Builder] Syntors at the salvage yard. Drive level to the 45 watt VHF PA?

[skipp025]

Re: Syntors at the salvage yard. 

Drive level to the 45 watt VHF PA? 

    

Yesterday we made it over to a longtime friend's Government 
Surplus Buyer/Seller/Dealer location/warehouse. He's got a 
great deal on LaMarche rack mount battery chargers if anyone 
is seriously looking for one. 

In one portion of his facility/building... he scrapped a 
fair number of VHF Syntor mobiles for the estimated weight 
value of the aluminum heat sink (metal). A truly sad day 
for surplus Motorola Syntor radios ... 

All the circuit boards were removed and sitting in pile so 
I picked up and purchased (cheap) a fair number of the 45 
watt RF PA PC-Boards (still in darn good shape). 

So...  can anyone quickly tell me the drive level? 

Board has two transistor stages 
driver M9860 
final M2511 
reported output power rating 45 watt. 

thanks 
skipp 
skipp025 at yahoo.com 

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Rick Beatty]

Hi All -- Here is my take on the preamp vs no preamp situation -- and with
Vertex repeaters --

First -- Preamps are not the solution to most of our troubles, in fact it
has been my experience over the years that they are more trouble than they
are helpful
I agree with Skipp and others when it is said to get rid of the LMR-400 and
replace it. For inside the box use 142b or 223, something with low loss but
is manageable to use on the duplexer and interconnects. rg-214 is way over
the top for most of this stuff. For antennas, don't use less than 1/2
heliax. Even '214 will get noisy if there is any flex or it is out in the
weather a couple of seasons.

No-Preamps, we as amateurs look a preamps as a panacia for many things,
including the lack of perceived receiver sensitivity. But it is interesting
to note a couple of things. One, a 0.4 uv receiver is as good as it is going
to get, in most cases because of the fact your setting in a high place and
the MDS combined with the power out, 50 to 75 watts, is going to be about
equal with a 4 pole antenna. Not rocket science, and you can actually run
that test iif your on a hill and have the proper equipment to do so.
Secondly, preamps, even at 10 db gain, really only add about 3 db of signal
and the rest is just moving the noise floor higher. And in some cases really
create a need for more signal to open the repeaters receiver. If your having
issues with the reciever, it would be my recommendation to set down and take
a hard look at the equipment, duplexer, antenna, and cables. There are so
many variables here in just those 4 items that it will take sometime to
optimize each of them to your needs.

Coax, again I agree with all of those on here that LMR, 214, 213, RG-8 etc
on a repeater is just not a good idea. Use hardline -

Vertex, I have nothing bad to say abobut them other than my experience with
2 UHF machines. Both of them exhibit the same characterisitcs so I will just
speak in general terms. What I found was that there was/is a lot of
crosstalk in the repeater box itself and even though the duplexer was well
tuned we could not get the isolation down on the system as a whole. The
second problem I found was that the LO runs all the time! This not good it
interferes with others on the site and can cause strange mixes within the
box that could desense your receiver, especially if there is a signal within
the IF of the repeater, either high or low.

How did we fix it? We went to a GE box, LOL!

So, I guess in conclusion here, before spending your hard earned dollars,
for preamps, helical resonators, and the like take good gander at the
situation and try to break it down to a common denominator, with a clear
picture as to what your seeing. Do all of the things necessary for good
repeater operation and then look again. I'll bet you just haven't found the
right place to look yet.

rick NU7Z


On Thu, Feb 5, 2009 at 10:18 AM, skipp025  wrote:

>   Hi Ralph,
>
> > Ralph  wrote:
> > I have never seen or used a Hamtronics preamp. I don't
> > know anything about their specs or how truthful they
> > are. Maybe some one out there in the great bits might
> > have an answer. Skipp? Eric? anyone??
>
> I'll answer up to the anyone label...
>
> Through the years Hamtronics has offered up a number of
> quite different RF Preamplifier kits and assembled boards.
>
> Relative to the industry they are truthful and their
> products are a good dollar value. Even more valuable is
> the experience and knowledge many people receive for
> constructing and setting up their kits.
>
> The RF Preamplifier you're probably talking about is not
> a true helical filter design. Hamtronics no longer offers
> the HRA series with the on board Toko (brand) helical
> filter. Their current products (when I last looked) were
> broad-band and some with modest tuned circuits, which is
> not really a true helical layout.
>
> After completing a recent very large vhf receiver site
> distribution project... I'm now not so keen on using
> and depending on or trusting the classic (Toko) type Helical
> filter assemblies in front receiver pre-amplifiers at locations
> with strong adjacent signals. The shining star in this
> most recent project was the now famous GLB pre-amplifier.
>
> Please don't confuse my description of the small Toko
> helical filter assemblies with the helical filters built
> into many receiver front end circuits/layouts. However, both
> the performance of your receiver can be and is often directly
> related to both... but you often can't easily change the
> receiver (as-built) front end assembly. "You get what you
> get" built into the receiver as supplied by the manufacturer.
>
> After reading your posts and all the answers... I can
> write is how I personally would want to know more about the
> Vertex radio receiver front-end layout before I started
> making changes. Directly dependent on the receiver front-
> end layout and performance... would say a lot about what
> you can successfully p

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[skipp025]

Hi Ralph, 

> Ralph  wrote:
> I have never seen or used a Hamtronics preamp. I don't 
> know anything about their specs or how truthful they 
> are. Maybe some one out there in the great bits might 
> have an answer. Skipp? Eric? anyone?? 

I'll answer up to the anyone label... 

Through the years Hamtronics has offered up a number of 
quite different RF Preamplifier kits and assembled boards. 

Relative to the industry they are truthful and their 
products are a good dollar value. Even more valuable is 
the experience and knowledge many people receive for 
constructing and setting up their kits. 

The RF Preamplifier you're probably talking about is not 
a true helical filter design. Hamtronics no longer offers 
the HRA series with the on board Toko (brand) helical 
filter. Their current products (when I last looked) were 
broad-band and some with modest tuned circuits, which is 
not really a true helical layout.

After completing a recent very large vhf receiver site 
distribution project... I'm now not so keen on using 
and depending on or trusting the classic (Toko) type Helical 
filter assemblies in front receiver pre-amplifiers at locations 
with strong adjacent signals. The shining star in this 
most recent project was the now famous GLB pre-amplifier. 

Please don't confuse my description of the small Toko 
helical filter assemblies with the helical filters built 
into many receiver front end circuits/layouts. However, both 
the performance of your receiver can be and is often directly 
related to both... but you often can't easily change the 
receiver (as-built) front end assembly. "You get what you 
get" built into the receiver as supplied by the manufacturer. 

After reading your posts and all the answers... I can 
write is how I personally would want to know more about the 
Vertex radio receiver front-end layout before I started 
making changes. Directly dependent on the receiver front- 
end layout and performance... would say a lot about what 
you can successfully park in front of it (the receiver). 

My personal suggestion is that you replace the LMR-400 
coax with almost anything else... with relatively short 
VHF lengths RG-214 mil spec is probably a great choice 
if you don't have access to free-bee (gratis) hard line. 

As previously reported many times... I source a lot of 
repeater problems back to LMR-400 cable so I jerk it out 
of all our duplex (repeater)operations. The Internet Wifi 
guys like and swear by it a lot (because of the lower cost) 
but their operations are mostly half duplex (simplex). 
Half duplex radio operations don't appear to suffer the 
LMR-400 type grunge problem nearly as much as the many 
repeater (full-duplex) gremlins we've had to resolve. But 
I have seen a fair number of Wifi problems related to 
using LMR-400 but a lot of that sort of blame gets put 
off on the path being bad or co-channel interference. 

It's very smart of you to pay attention to the antenna 
beam-width related to both your elevation and location of 
the majority users. 

A smaller part about how much Transmit Power you use is 
modestly inter-related to your hardware and how hot you 
want the receiver side of things. Less TX Power Out is 
easier to deal with... but I do like a very solid TX 
signal on/at the user end. 

There are a gazillion pre-amp and filter options possible... 
for me it comes full circle back to the receiver performance 
and how it's laid out (constructed). 

Commercial mobile two-way radios can be decent repeater 
receivers and some can be "not so good". 

cheers, 
skipp 

RE: [Repeater-Builder] mobile duplexer

[Eric Lemmon]

Mike,

What band is this link on, and what RX-TX separation is used?

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com 
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Michal Smialowski
Sent: Wednesday, February 04, 2009 7:57 AM
To: Repeater-builder@yahoogroups.com
Subject: [Repeater-Builder] mobile duplexer

 
 

I have been working on a duplex link which is running about 3 watts. I 
have a couple of mobile duplexers with four reject cavities.
One end of the link will be a remote mountain top unit. I get about 
70dB of reject of the transmit frequency on the receive side.
Yet when I connect it up to the repeater I seem to get an inordinate 
amount of desense which I didn't expect running only 3 watts. I am using a 
dummy load
for an antenna. I have been using an ISOTEE to inject the signal on the 
receive side. Does this sound normal for a mobile duplexer?
Thanks 
Mike VE7SML

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Chuck Kelsey]

I was thinking the same thing. It sounds like the poster's RX has good 
sensitivity as it is. LMR400 and antenna too close to repeater may be 
causing desense, thus the "indication" that receive isn't working as it 
should. Get rid of the LMR400 first and check for desense. If it's still 
there, move antenna further away and check again.

Chuck
WB2EDV



- Original Message - 
From: "Joe" 
To: 
Sent: Thursday, February 05, 2009 9:48 AM
Subject: Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or 
Advanced Research Preamp


>I agree.  I recently moved a 2 meter repeater to a temporary location
> with approx. 25 feet of coax and have problems.  I had to move the
> repeater cabinet around until I got rid of the desense.  A better site
> is in the planning, but we need to get rid of some snow first.
>
> 73, Joe, K1ike
>
> If your repeater cabinet and the antenna are only separated by 20' and
>>
>> you're operating on 2m, there's a very good chance you're going to have
>> other problems...
>>
>> --- Jeff WN3A

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Joe]

I agree.  I recently moved a 2 meter repeater to a temporary location 
with approx. 25 feet of coax and have problems.  I had to move the 
repeater cabinet around until I got rid of the desense.  A better site 
is in the planning, but we need to get rid of some snow first.

73, Joe, K1ike

If your repeater cabinet and the antenna are only separated by 20' and
>
> you're operating on 2m, there's a very good chance you're going to have
> other problems...
>
> --- Jeff WN3A
>
>
>
> 

Re: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Ralph S. Turk]

Most sites will NOT allow RG214 to be used outside. Use 1/2 hard line for runs 
less than 50-75 ft 
- Original Message - 
From: "Jeff DePolo"  
To: Repeater-Builder@yahoogroups.com 
Sent: Thursday, February 5, 2009 6:31:22 AM GMT -07:00 U.S. Mountain Time 
(Arizona) 
Subject: RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or 
Advanced Research Preamp 






> Again, 20 ft. of 7/8" for 2 meters is an unnecessary expense. 
> 20 ft. of 
> RG-214 has only 0.5 dB of loss @ 146 MHz - quite acceptable for a 
> first-rate system, and it won't cost you that much even if 
> you have to buy 
> it @ retail $$. 
> 
> Bob NO6B 

If your repeater cabinet and the antenna are only separated by 20' and 
you're operating on 2m, there's a very good chance you're going to have 
other problems... 

--- Jeff WN3A 

RE: [Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Jeff DePolo]

> Again, 20 ft. of 7/8" for 2 meters is an unnecessary expense. 
> 20 ft. of 
> RG-214 has only 0.5 dB of loss @ 146 MHz - quite acceptable for a 
> first-rate system, and it won't cost you that much even if 
> you have to buy 
> it @ retail $$.
> 
> Bob NO6B

If your repeater cabinet and the antenna are only separated by 20' and
you're operating on 2m, there's a very good chance you're going to have
other problems...

--- Jeff WN3A

[Repeater-Builder] Re: Hamtronics Helical Resonator Preamp or Advanced Research Preamp

[Bob Ricci]

I expect that two voted receivers is part of the solution. I have 
decided to either track down the commercial tower owner up the street 
whose tower is not registered with the FCC and put the repeater there, 
or move the antenna to the other side of the house and push it up 60 
feet. In this case I'll definitely use hard line.


--- In Repeater-Builder@yahoogroups.com, n...@... wrote:
>
> At 2/4/2009 22:17, you wrote:
> >Excellent advice, and thank you.
> >
> >We are experimenting with unity gain, 3dB, 6dB, and 9dB. The results
>