Re: [Repeater-Builder] Re: Coax length, etc.

[allan crites]

Jeff, 
My internet service was interrupted again tonight for 2 hrs as well as last 
night and I just got off the phone with the tech in MX city for 35 min till he 
restored the service. He wants to get me a new modem to solve my problem but 
can't deliver it until Tuesday at which time I will be back in the US.
So I respectfully decline to respond until then as there is no guarantee my 
service will continue uninterrupted.
AC




From: Jeff DePolo 
To: Repeater-Builder@yahoogroups.com
Sent: Fri, August 13, 2010 8:22:23 PM
Subject: RE: [Repeater-Builder] Re: Coax length, etc.

  
I'm going to take a stab at this, at the risk of possibly stepping on Gary's
toes.

1. RF amplifiers in general (not only solid state) don't *have* a 50 ohm
source impedance, they're (nominally) designed to work *into* a 50 ohm load.
The difference is subtle, but significant. Transmitters aren't classic
generators. 

2. GE offered the matching network on station PA's for a number of reasons,
among them:

a) Amplifier circuit designs (solid-state or otherwise) have a finite
bandwidth; a tuning network allows for some output matching adjustment

b) Ideally the transmitter will be looking into a nice 50+j0 load (assuming
that's what it was designed for), but the world isn't perfect, hence the
adjustable output matching network to correct for *minor* load mis-match
(strong emphasis on minor)

c) Although not explictly described in GE's tuning procedures, significant
improvement in efficiency can be obtained with proper tuning of the
Z-matcher. Tuning for 50+j0 at the input to the Z-matcher is NOT
necessarily the RIGHT match!

d) To charge more. I'm half-joking on this; I can't say I've statistically
seen more or less failures on M2 PA's with or without the Z-matcher, so I'll
give this answer half a smiley: .-,

3. As far as Gary's comment about off-channel Z and its effect on
transmitters, some sub-par (or damaged) PA's will go spurious when looking
into a load that presents a bad match off-channel, even if it presents a
nice flat load on-channel. Some manufacturers suggest playing with cable
lengths to "tame" misbehaving PA's. Again, this is a shortcoming in the
PA, and I, for one, am not into band-aid fixes for design flaws or defective
equipment; I fix (or replace) the PA. When I walk off the site, I want to
KNOW the PA is going to be stable in the future as the load changes, because
it WILL change...

As far as "optimium power transfer", anyone that has passed their tech test
probably already knows the textbook answer to that question (the maximum
power theorem). But that's not really the issue here, is it OM? Again, we
have to accept the fact that amplifiers aren't classic generators; we can't
just look at the problem from the perspective of power transfer into a 50
ohm load. We have to look at the devices being used in the PA, the networks
doing the impedance transformations, the behavior of the amplifier as a
whole (including all cascaded gain stages), its behavior as voltages and
temperature are varied, and, one of the most important parameters,
efficiency.

Just to back up a step, let's revisit the textbook answer of "optimum power
transfer", which again, is based on a classis generator. In such a case,
the optimum power transfer is the *maximum* power that is received by the
load. Well, in our little RF corner of the power transfer world, it's not
that simple. We're not out eek the last watt out of our amplifier - that's
not the goal (or at least it shouldn't be). We all know we can sometimes
squeeze a fraction of a dB more out of an amplifier by purposefully
mis-loading it, but is that "a good thing"? Does that make it an "optimum"
match? Hell no. Among other things, we need to look at *efficiency*, and
plotting that against power output if we want to find the sweet spot.
Efficiency is a primary performance metric for RFPA matching, especially
when it comes to continuous-duty solid-state RFPA's where heat is your worst
enemy. 

As far as SS VHF/UHF amplifiers go, good RFPA design should dictate that you
have adequate hardware headroom such that you're not stressing the devices
or any support components to make rated output, so "maximum power transfer"
should be the least of the worries for the tech tuning the equipment.
Stability and spectral purity should be a given in a properly-designed RFPA.
So the only parameter that should need to be monitored during
fine-adjustment at the output is really efficiency/current draw if
everything else was done right from the get-go.

--- Jeff WN3A

> -Original Message-
> From: Repeater-Builder@yahoogroups.com 
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of allan crites
> Sent: Friday, August 13, 2010 5:41 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] Re: Coax length, etc.
> 
> 
> 
> Gary,
> Perhaps you can give us some examples to illustrate your thoughts.
> Perhaps you can also explain why GE chose to include

RE: [Repeater-Builder] unsubscribe

[Richard]

Well, I think it's funny.
 

Richard, N7TGB
www.n7tgb.net
The problem with socialism is that eventually you run out of other people's
money
--Margaret Thatcher


 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Kenneth Cook
Sent: Friday, August 13, 2010 9:27 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] unsubscribe


  



 
This is an experiment to see if I could make the link stand out. This is NOT
to start problems!

73.de Ken Cook, W8DZN

 

Yahoo! Groups

Switch to:
 Text-Only,
 Daily Digest .

Unsubscribe .   Terms of Use

.

 
 

RE: [Repeater-Builder] unsubscribe

[Kenneth Cook]

 
This is an experiment to see if I could make the link stand out. This is NOT
to start problems!

 

73.de Ken Cook, W8DZN

 

Yahoo! Groups

Switch to:
 Text-Only,
 Daily Digest .

Unsubscribe .   Terms of Use

.

 
 

Re: [Repeater-Builder] Re: Coax length, etc.

[Nate Duehr]

On Aug 13, 2010, at 7:22 PM, Jeff DePolo wrote:

> d) To charge more. I'm half-joking on this; I can't say I've statistically
> seen more or less failures on M2 PA's with or without the Z-matcher, so I'll
> give this answer half a smiley: .-,

Lucky.  I have.  Learned that lesson... ;-)

Got a pile of dead VHF MII PA's in the garage to prove it, too.  :-)

One particular site with a shared TX antenna system... hybrids even, so the 
darn thing has isolators sprouting from every orifice... 

Something about it just never sat well with the VHF MASTR II PAs.  Z-matcher 
installed, running many years now...

--
Nate Duehr
n...@natetech.com

Re: [Repeater-Builder] Re: Coax length, etc.

[Nate Duehr]

Allan, 

Wow... sounds like a great article you guys are working on!  Now that I see the 
scope of what you're up to, it sounds like a great addition to the website.  
(Well, it would have been a great addition anyway... but wow!)

You give me FAR too much credit, if you think I could add to it.  My knowledge 
is barely able to keep up with most folks 'round here!  

I just mentioned the Antenna Book, 'cause I ended up with a copy one year (only 
thing I've ever won at a hamfest) and should have spent the $70 (at the time) 
to have bought a copy YEARS before I won that one.  It really is an excellent 
book, well worth the $!

--
Nate Duehr
n...@natetech.com

Re: [Repeater-Builder] OT: Licensing Exam Info

[Nate Duehr]

On Aug 13, 2010, at 7:17 AM, Mark Tomany wrote:

> Well if you think about it, Nate, VE's ARE an off-site testing facillity... 
> of sorts.
>  
> Mark - N9WYS (also a pilot)

Heh, good points all.  Just had a "hmm, that's interesting" thought in the 
middle of the night, that wasn't so interesting after all! ;-)

--
Nate Duehr
n...@natetech.com

Re: [Repeater-Builder] Need low power PA mod help for VHF MVP

[Kevin Custer]

Thomas Oliver wrote:



I am in need of a 2-5 watt range amp to drive an external amplifier, 
the stock VHF MVP amp is adjustable from 8-25 watts output,


I think by bypassing Q202 I will be close to my goal.  I need to know 
where to connect the coax to keep Q201 from getting mad.


I have done this on UHF MVP's before but the VHF amp is coupled 
differently between stages.


Schematic here:  www.repeater-builder.com/ge/lbi-library/lbi-30143a.pdf


Try removing Q202 and placing a coupling capacitor between the pads 
where the Base and Collector were.  Something between 100 and 470 pF 
should do it.  I'd use a silver mica with short leads.


Kevin

Re: [Repeater-Builder] Tait T296 PSU Circuit

[Mike Morris]

At 06:44 PM 08/13/10, you wrote:

can i pls have a copy of it, even if need be 
yousendit.com to me


Go to www.repeater-builder.com then to Tait then right click on it 
and download it.

Re: [Repeater-Builder] Coax length, etc.

[Kevin Custer]

Jeff DePolo wrote:


Maybe I'm not understanding right.  Are you saying that by varying the cable
length between the transmitter and the duplexer that you can affect the
insertion loss of the duplexer?


No. 

Because the impedance is not matched between the transmitter and 
duplexer, the 'apparent' loss of the duplexer is greater than the 
manufacturers stated loss of the duplexer.  Changing the cable length is 
not changing the loss of the duplexer, it's changing the power that is 
accepted at the transmitter port of the duplexer by matching the output 
impedance of the transmitter to the input impedance of the transmitter 
port of the duplexer.



  And also that by varying the cable length between the transmitter and the 
duplexer that you can vary the reflected
power on that same line?


Yes.

In a situation where the duplexer and transmitter have differing 
impedances, and a cable optimized in length matches these impedances, 
the mismatch at the duplexer is minimized, therefore the power reflected 
by the duplexer is minimized. 


  Please tell me I'm reading this wrong...I've been
on the road a long time and working a lot of long hours, so it's quite
possible...

--- Jeff WN3A


I have found that when you get a transmitter that is 'picky' about the 
length of interconnecting cable, power being read at the output port of 
the duplexer is low and you cannot alter the tuning of the cavity 
closest to the transmitter to make things right.  In other words, the 
place where lowest VSWR and maximum power transfer occurs is at two 
completely different places, and power transfer is not up where it 
should be (transmitter makes 100 watts into a dummy load but only shows 
50 watts on the output port of the duplexer that has a stated 1.5 dB 
loss (29 %)).  As you get close to the 'optimum' cable length, the 
lowest VSWR and maximum power transfer occur near the same place when 
tuning the cavity closest to the transmitter.


I usually pay more attention to what is coming out the antenna port of 
the duplexer - first.  Then, when things are right, comparing forward 
power going to the duplexer and power going to a good dummy load will be 
very close the same, since matching the impedance of the transmitter to 
the impedance of the duplexer was accomplished by some means.


I use a compensation cable along with my Bird so that the samplers 
transmission line length is nullified in the line under test.  This 
compensation cable results in exactly 1/2 WL including the samplers 
transmission line.  Compensation cable lengths are outlined in the 
manual for the Bird 43.


Kevin

[Repeater-Builder] Need low power PA mod help for VHF MVP

[Thomas Oliver]

I am in need of a 2-5 watt range amp to drive an external amplifier, the 
stock VHF MVP amp is adjustable from 8-25 watts output,


I think by bypassing Q202 I will be close to my goal.  I need to know 
where to connect the coax to keep Q201 from getting mad.


I have done this on UHF MVP's before but the VHF amp is coupled 
differently between stages.


Schematic here: www.repeater-builder.com/ge/lbi-library/lbi-30143a.pdf


tom

[Repeater-Builder] Re: Tait T296 PSU Circuit

[niteviser]

In the Files section Marcus. 296-01 PS as a jpeg. It is all I have on it, but 
it was with the 296/11 and /16 circuits, which are slightly different.

niteviser

--- In Repeater-Builder@yahoogroups.com, "x.tait.tech"  wrote:
>
> can i pls have a copy of it, even if need be yousendit.com to me
> 
> i have a circuit here somewhere, but fail so far to find it, and i know  i
> don't have it online
> 
> Marcus
> 
> 
> 
> On Sat, Aug 14, 2010 at 11:58 AM, Gordon Cooper  wrote:
> 
> >
> >
> > niteviser,
> > Thanks a lot, circuit downloaded without trouble.
> >
> > Gordon ZL1KL
> >  
> >
>

Re: [Repeater-Builder] unsubscribe

[Jim in Waco WB5OXQ]

I will stay but switched to digest
  - Original Message - 
  From: ka9qjg 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, August 13, 2010 8:15 PM
  Subject: RE: [Repeater-Builder] unsubscribe




  Hate to see Ya Go  but if You must here is one More You will get , You 
subscribed and You have to Unsubscribe Yourself  unless You get kicked off , At 
the Bottom of the Page You will see Where  to do it  You can also set up how 
You would like to receive the E-Mails 



  73 De Don KA9QJG 



  From: Repeater-Builder@yahoogroups.com 
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Jim in Waco WB5OXQ
  Sent: Friday, August 13, 2010 7:57 PM
  To: Repeater-Builder@yahoogroups.com
  Subject: [Repeater-Builder] unsubscribe





  I do not need to read these anymore.  I am not mad just getting too many 
emails.



  


--



  No virus found in this incoming message.
  Checked by AVG - www.avg.com 
  Version: 9.0.851 / Virus Database: 271.1.1/3069 - Release Date: 08/13/10 
13:34:00

Re: [Repeater-Builder] Tait T296 PSU Circuit

[x.tait.tech]

can i pls have a copy of it, even if need be yousendit.com to me

i have a circuit here somewhere, but fail so far to find it, and i know  i
don't have it online

Marcus



On Sat, Aug 14, 2010 at 11:58 AM, Gordon Cooper  wrote:

>
>
> niteviser,
> Thanks a lot, circuit downloaded without trouble.
>
> Gordon ZL1KL
>  
>

Re: [Repeater-Builder] Re: Mirage B-320-G as a Repeater Amp

[x.tait.tech]

throw away the duplexer and get another

i seem to read everything you state it is fine until i plug in the duplexor
inline

at least if not, do you have another duplexer to try in its place


Marcus





On Sat, Aug 14, 2010 at 1:29 PM, Jeff DePolo  wrote:

>
>
> > The amp does fine without the duplexer inline. Full power and
> > it follows the Mirage chart. But I had a thought (that's
> > SCARY) I pulled out my seldom used MFJ 259 and dialed in my
> > output. I plugged it into the duplexer TX side and noted that
> > it reads 39 ohms. I disconnected the remaining two cans and
> > attached a dummy load to the output of the can and still read 39 ohms.
> >
> > I'm not sure what conclusion to take from this. I mean, low tech!
>
> What does the dummy load alone read?
>
> How about my other question - do you have "grunge" with the repeater
> transmitter NOT keyed (i.e. just listening on the local repeater receiver
> with the repeater transmitter disabled)?
>
> > Thank you for your best wishes re: my daughter. She has had a
> > tremendously bad week. The high dose chemo has burned her
> > body and worse that I won't share. But she's a sick little 8
> > year old. http://princessrachael.com
>
> Tried to go to the URL but it took me to some other web site and asked me
> to
> log in?
>
> Again, best wishes. I have a 1 year old and a 3 year old, they're my best
> buddies, I can't imagine what you're going through.
>
> --- Jeff WN3A
>
>  
>

RE: [Repeater-Builder] Coax length, etc.

[Jeff DePolo]

I must have missed some posts - my inbox ran out of space (I'm on the road
and not checking email as often as I usually do), so my apologies if I'm
asking questions that have already been answered... 

> > Allan Crites and I are currently in discussion which will 
> be used as the basis of a RB web article that will explain 
> exactly what is happening, why it happens, and why an 
> 'optimized' cable length can be used to transfer power ending 
> up with the stated loss of the duplexer and have little 
> reflected power toward the transmitter - so long as the 
> duplexer is tuned properly and exhibits good return loss on 
> the frequency it's designed to pass.

Maybe I'm not understanding right.  Are you saying that by varying the cable
length between the transmitter and the duplexer that you can affect the
insertion loss of the duplexer?  And also that by varying the cable length
between the transmitter and the duplexer that you can vary the reflected
power on that same line?  Please tell me I'm reading this wrong...I've been
on the road a long time and working a lot of long hours, so it's quite
possible...

--- Jeff WN3A

RE: [Repeater-Builder] Re: Mirage B-320-G as a Repeater Amp

[Jeff DePolo]

> The amp does fine without the duplexer inline. Full power and 
> it follows the Mirage chart. But I had a thought (that's 
> SCARY) I pulled out my seldom used MFJ 259 and dialed in my 
> output. I plugged it into the duplexer TX side and noted that 
> it reads 39 ohms. I disconnected the remaining two cans and 
> attached a dummy load to the output of the can and still read 39 ohms.
> 
> I'm not sure what conclusion to take from this. I mean, low tech!

What does the dummy load alone read?

How about my other question - do you have "grunge" with the repeater
transmitter NOT keyed (i.e. just listening on the local repeater receiver
with the repeater transmitter disabled)?

> Thank you for your best wishes re: my daughter. She has had a 
> tremendously bad week. The high dose chemo has burned her 
> body and worse that I won't share. But she's a sick little 8 
> year old. http://princessrachael.com

Tried to go to the URL but it took me to some other web site and asked me to
log in?

Again, best wishes.  I have a 1 year old and a 3 year old, they're my best
buddies, I can't imagine what you're going through.

--- Jeff WN3A

RE: [Repeater-Builder] Re: Coax length, etc.

[Jeff DePolo]

I'm going to take a stab at this, at the risk of possibly stepping on Gary's
toes.

1. RF amplifiers in general (not only solid state) don't *have* a 50 ohm
source impedance, they're (nominally) designed to work *into* a 50 ohm load.
The difference is subtle, but significant.  Transmitters aren't classic
generators. 

2.  GE offered the matching network on station PA's for a number of reasons,
among them:

a) Amplifier circuit designs (solid-state or otherwise) have a finite
bandwidth; a tuning network allows for some output matching adjustment

b) Ideally the transmitter will be looking into a nice 50+j0 load (assuming
that's what it was designed for), but the world isn't perfect, hence the
adjustable output matching network to correct for *minor* load mis-match
(strong emphasis on minor)

c) Although not explictly described in GE's tuning procedures, significant
improvement in efficiency can be obtained with proper tuning of the
Z-matcher.  Tuning for 50+j0 at the input to the Z-matcher is NOT
necessarily the RIGHT match!

d) To charge more.  I'm half-joking on this; I can't say I've statistically
seen more or less failures on M2 PA's with or without the Z-matcher, so I'll
give this answer half a smiley:   .-,

3.  As far as Gary's comment about off-channel Z and its effect on
transmitters, some sub-par (or damaged) PA's will go spurious when looking
into a load that presents a bad match off-channel, even if it presents a
nice flat load on-channel.  Some manufacturers suggest playing with cable
lengths to "tame" misbehaving PA's.   Again, this is a shortcoming in the
PA, and I, for one, am not into band-aid fixes for design flaws or defective
equipment; I fix (or replace) the PA.  When I walk off the site, I want to
KNOW the PA is going to be stable in the future as the load changes, because
it WILL change...

As far as "optimium power transfer", anyone that has passed their tech test
probably already knows the textbook answer to that question (the maximum
power theorem).  But that's not really the issue here, is it OM?  Again, we
have to accept the fact that amplifiers aren't classic generators; we can't
just look at the problem from the perspective of power transfer into a 50
ohm load.  We have to look at the devices being used in the PA, the networks
doing the impedance transformations, the behavior of the amplifier as a
whole (including all cascaded gain stages), its behavior as voltages and
temperature are varied, and, one of the most important parameters,
efficiency.

Just to back up a step, let's revisit the textbook answer of "optimum power
transfer", which again, is based on a classis generator.  In such a case,
the optimum power transfer is the *maximum* power that is received by the
load.  Well, in our little RF corner of the power transfer world, it's not
that simple.  We're not out eek the last watt out of our amplifier - that's
not the goal (or at least it shouldn't be).  We all know we can sometimes
squeeze a fraction of a dB more out of an amplifier by purposefully
mis-loading it, but is that "a good thing"?  Does that make it an "optimum"
match?  Hell no.  Among other things, we need to look at *efficiency*, and
plotting that against power output if we want to find the sweet spot.
Efficiency is a primary performance metric for RFPA matching, especially
when it comes to continuous-duty solid-state RFPA's where heat is your worst
enemy.  

As far as SS VHF/UHF amplifiers go, good RFPA design should dictate that you
have adequate hardware headroom such that you're not stressing the devices
or any support components to make rated output, so "maximum power transfer"
should be the least of the worries for the tech tuning the equipment.
Stability and spectral purity should be a given in a properly-designed RFPA.
So the only parameter that should need to be monitored during
fine-adjustment at the output is really efficiency/current draw if
everything else was done right from the get-go.

--- Jeff WN3A




> -Original Message-
> From: Repeater-Builder@yahoogroups.com 
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of allan crites
> Sent: Friday, August 13, 2010 5:41 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: Re: [Repeater-Builder] Re: Coax length, etc.
> 
>   
> 
> Gary,
> Perhaps you can give us some examples to illustrate your thoughts.
> Perhaps you can also explain why GE chose to include a pi 
> network on the output of the HB M-2 base xmtr to match the 
> xmtr output to 50 Ohms, the shunt capacitor values and the 
> series inductor value used.
> I'm interested to hear your explaination on how you would 
> determine the length of cable needed.
> AC
> 
> 
> 
> From: Gary Schafer 
> To: Repeater-Builder@yahoogroups.com
> Sent: Fri, August 13, 2010 2:36:23 PM
> Subject: RE: [Repeater-Builder] Re: Coax length, etc.
> 
>   
> 
> Hi Allan,
> 
>  
> 
> Do we really care what the output impedance of the 

RE: [Repeater-Builder] unsubscribe

[ka9qjg]

Hate to see Ya Go  but if You must here is one More You will get , You
subscribed and You have to Unsubscribe Yourself  unless You get kicked off ,
At the Bottom of the Page You will see Where  to do it  You can also set up
how You would like to receive the E-Mails 

 

73 De Don KA9QJG 

 

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Jim in Waco WB5OXQ
Sent: Friday, August 13, 2010 7:57 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] unsubscribe

 

  

I do not need to read these anymore.  I am not mad just getting too many
emails.

[Repeater-Builder] unsubscribe

[Jim in Waco WB5OXQ]

I do not need to read these anymore.  I am not mad just getting too many emails.

[Repeater-Builder] Tait T296 PSU Circuit

[Gordon Cooper]

niteviser,
Thanks a lot, circuit downloaded without trouble.

Gordon ZL1KL

[Repeater-Builder] Re: Sorry everyone

[Bob - AF6D]

I haven't read all of the relies on this, but I also haven't read that there is 
proof that your computer actually sent the messages. All that is needed is your 
email address int he reply-to field in the message header and you get the 
blame. I own and operate a mid-sized web hosting company and we deal with spam 
issues daily. Recipients running anti-spam software that rejects and sends back 
to the real sender actually end up causing backscatter and getting their own IP 
blacklisted. SPAM will never end...

--- In Repeater-Builder@yahoogroups.com, Dave E Stephens Sr  wrote:
>
> i would like to thank all of you for understanding. right after i sent out my 
> original appology i figured out which computer might be sending the cause of 
> this. not long ago i got mom a new HP laptop. She wanted a computer just so 
> she could play a few games. well mom is what i call a techno-tard (didnt even 
> know how to turn it on). Before i knew it, her friend got her on facebook 
> playing farmville and who knows what. Its the WHO KNOWS WHAT that i am 
> worried about. 
>  
> not long ago the YL was over there on the computer, checking her email. next 
> day i discovered her account sent out a similar email to what mine sent. i 
> used it the day before yesterday and BAM, i discover the same email sent out. 
>  
> There is no evidence of a message being sent in my sent box here on Yahoo BUT 
> i got 2 replys saying they couldnt be delivered. 
>  
> I was going to fix the issue yesterday but i got busy. AVG and Spybot S&D 
> will be installed a little later on today. 
>  
> You know, its funny... i spend 8 to 12 hours a day, 6 to 7 days a week, 
> dealing with this issue and others like that. For 16 years i have never had 
> an account of mine hit till now. i am supprised it didnt hit sooner. 
>  
> Thanks again everyone for understanding... 73's
>  
> Dave Stephens Sr
> KF6WJA
> Grants Pass Or
>  
>  
>  
> 
> --- On Thu, 8/12/10, Mark Tomany  wrote:
> 
> 
> From: Mark Tomany 
> Subject: Re: [Repeater-Builder] Sorry everyone
> To: Repeater-Builder@yahoogroups.com
> Date: Thursday, August 12, 2010, 6:51 AM
> 
> 
>   
> 
> 
> 
> 
> 
> 
> 
> 
> AVG Free anti-virus software also has a built-in spyware removal tool.  I 
> also use the ones George captioned below - and even I get bit every once in a 
> while by some new bug.
>  
> It's amazing that so many people have the time on their hands to be able to 
> propagate all this crap...
>  
> Mark - N9WYS
> 
> --- On Wed, 8/11/10, George Henry wrote:
> 
> Nonsense!  Spybot Search & Destroy, Ad-Aware, Malwarebytes Anti-Malware, and 
> SuperAntiSpyware are all EXCELLENT free anti-spyware programs.  I routinely 
> use all 4 of them to clean up infections for people.  No spyware in ANY of 
> them and, between the four programs, I have yet to run into something I 
> couldn't clean.
> 
> 
> George, KA3HSW / WQGJ413 
> 
> - Original Message - 
> From: "Tim Sawyer"
> 
> >Was your machine on while you were away? If so you may have gotten a virus 
> >or spyware. Sounds like your wife got it too. Spamers like to >infect 
> >machines just to get control of them for sending spam. The really bad news 
> >is that most free spyware removal software is spyware itself. A >really 
> >good PC guy might be able to remove it. Good luck man!
> >--
> >Tim
>

[Repeater-Builder] Re: TKR-750 Crunchy/Grungy Weak Signal Audio

[Bob - AF6D]

I have a DB224-E on order along with hard line and a receive filter and crystal 
assembly. It seems that I have a 147.435 high power remote with a 12 element 
beam and 600 watts aimed through me from 1.105MHz away and only two city 
blocks. The 435 repeater is legendary. We've picked up commitments for public 
safety nets throughout the week and I need to get as much done on a limited 
budget as possible. Funny thing, members don't pay to join the ARC UNTIL it is 
dialed and tweaked.

--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
>
> Probably the LMR-400 cable is the cause. Well documented and discussed here 
> regularly. Are the other repeaters with the same problem also using the same 
> type cable?
> 
> Chuck
> WB2EDV
> 
> 
> 
> - Original Message - 
> From: "Bob - AF6D" 
> To: 
> Sent: Monday, August 09, 2010 4:46 AM
> Subject: [Repeater-Builder] TKR-750 Crunchy/Grungy Weak Signal Audio
> 
> 
> > My 2 meter TKR has worked fine for about a year but has always had a 
> > problem on our frequent weak signals. We're a mountain community and 
> > CERT/RACES/ARES/Skywarn users are often on HT's. There are a couple of 
> > towers in the neighborhood at 6,400 feet over southern California (it's 
> > kewl living at a repeater site) and on my own gear I don't hear anything 
> > on a weak signal beyond the norm. But on the TKR it just sounds dirty. 
> > Grungy. Crunchy. There are commercial sites within one mile with high 
> > power paging but we've detected no intermod. We did have a bout were 
> > grungy audio was breaking PL and hanging until timeout. But that went 
> > away. The Wacom 6 cavity WP-642 is tuned dead on and offers excellent 
> > isolation and rejection (at a cost of 2-3dB loss on TX ).
> >
> > Another TKR user at a high elevation commercial site reports similar 
> > experiences. Yet another TKR owner reported that his is excellent and yes 
> > the audio is good. Just not for us on weak signals. He suggested perhaps 
> > an RFI issue but from where?
> >
> > Our installation is modest and constrained only by my lack of time and 
> > funds. My daughter is sick and I live in a hospital with her, so be gentle 
> > HI HI. The very large guard dog watches the house.
> >
> > The antenna is a Hustler G5-144 tuned with a MFJ 259, dead on and above 
> > the repeater through an insulated roof by about 30 feet. We have no 
> > desense. It is fed with LMR-400 just because I haven't put hard line on 
> > it. No preamps are installed. At 6,400 feet not much is needed. The 
> > receiver is .18uV. The TKR hears very well compared to my FT-847 with an 
> > antenna 20 feet lower.
> >
> > Why the grungy audio?
> >
> >
> >
> >
> >
> > 
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> 
> 
> 
> 
> 
> 
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.851 / Virus Database: 271.1.1/3059 - Release Date: 08/08/10 
> 13:57:00
>

Re: [Repeater-Builder] Re: Coax length, etc.

[allan crites]

Gary,
Perhaps you can give us some examples to illustrate your thoughts.
Perhaps you can also explain why GE chose to include a pi network on the output 
of the HB M-2 base xmtr to match the xmtr output to 50 Ohms, the shunt 
capacitor 
values and the series inductor value used.
I'm interested to hear your explaination on how you would determine the length 
of cable needed.
AC




From: Gary Schafer 
To: Repeater-Builder@yahoogroups.com
Sent: Fri, August 13, 2010 2:36:23 PM
Subject: RE: [Repeater-Builder] Re: Coax length, etc.

  
Hi Allan,
 
Do we really care what the output impedance of the transmitter is? Most 
transmitters do not present a pure 50 ohm output but are tuned to transfer 
maximum power into a 50 ohm load. This often comes out to something way 
different than a 50 ohm source impedance.
As the source impedance does not affect SWR the system doesn’t care what it is 
as long as the transmitter can transfer maximum power into 50 ohms.
 
What the transmitter does sometimes care about is the reflected impedance from 
the first cavity (being hi Q) that is not on frequency. This presents a highly 
reactive load to the transmitter that can sometimes cause the transmitter to 
overheat or reduce output. Placing a cable of a different length between output 
and the first cavity can sometimes change the unwanted off frequency load seen 
by the transmitter.
 
73
Gary  K4FMX
 



From:Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] 
On Behalf Of allan crites
Sent: Friday, August 13, 2010 12:56 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Coax length, etc.
 



Nate,
I have both the 12th and 14th edition of the ARRL Antenna books, the 12th I 
acquired in 1974 and have read and re-read the section on transmission lines 
and 
impedance matching probabily more than anyone else has. I sometimes learn new 
things with each re-reading, as there is much to be learned.
In my discussions with Kevin Custer about the length of the transmission line 
connecting the xmtr output and the input to the duplexer, he suggested and I 
accepted, to colaborate on an article explaining the problems associated with 
matching the output impedance of a solid state transmitter of somewhat 
different 
than the normal 50 Ohms, and the attempts made by a manufacturer of duplexers 
to 
adapt (read match) the xmtr output via certain lengths of transmission line and 
readjustment of the tuning of the cavity closest to the xmtr output to effect 
this matching,  ignoring the possible degradation resulting to the pass and 
notch characteristics.  
The transmitter in our discussions was the HB GE Mastr 2 which, in the 
information available to me, appears to be having an output source impedance of 
35+ or - (some unknown) reactance Ohms.
Kevin commented that it appears that many hams are unaware of, or understand 
the 
methods needed, to do an appropriate job of impedance matching.
Therefor we will be making this article for the benefit of those who don't 
understand the impedance matching necessary for optimum power transfer with a 
simple to understand way of impedance matching without the use of the 
infamous Smith Chart (which I have utilized for the past 50 yrs in all my 
impedance matching solutions and cannot be without).
I agree that much information for impedance matching is contained in the ARRL 
Antenna Book but in my experience, real life adaptation of this information is 
and can be difficult to many hams.
There is also another book I rely on and recommend, which is  "Electronic 
Applications of the Smith Chart" by Philip Smith.
Now, if you would like to contribute to our efforts I would gladly accept your 
contributions.
Thanks for your input.
Allan Crites  wa9zzu
 



From:Sid 
To: Repeater-Builder@yahoogroups.com
Sent: Fri, August 13, 2010 10:38:25 AM
Subject: [Repeater-Builder] Re: Coax length, etc.

  
I have a note in my file that I do not recall where it came from relative to 
cable length between the duplexer and the TX or between the duplexer and 
additional filter. Length = (30)(32.785)(vf/freq).
30 is for 30 degrees, vf is velocity factor, freq is the average of the pass 
and 
reject frequencies. If too short add 180 degrees. Don't know if this is good 
info or not. The article would be appreciated. Sid. 



--- In Repeater-Builder@yahoogroups.com, Nate Duehr  wrote:
>
> 
> On Aug 5, 2010, at 11:20 AM, Kevin Custer wrote:
> 
> > Allan Crites and I are currently in discussion which will be used as the 
>basis of a RB web article that will explain exactly what is happening, why it 
>happens, and why an 'optimized' cable length can be used to transfer power 
>ending up with the stated loss of the duplexer and have little reflected power 
>toward the transmitter - so long as the duplexer is tuned properly and 
>exhibits 
>good return loss on the frequency it's designed to

Re: [Repeater-Builder] RG-223 - RG-142 & RG-400 Coax Talk

[no6b]

At 12:05 PM 8/12/2010, you wrote:


>RG-223 - RG-142 & RG-400 Coax Talk
>
> > "Sid"  wrote:
> > I have seen a lot of jumpers, interconning cables,
> > duplexer cables, etc made using RG-142 and RG-400 (the
> > 400 is preferred). However, RG-223 is also silver,
> > double shielded,very flexible, and also about RG-58 size.
> > Any reason why RG-223 would not work just as well; other
> > than it is not a teflon cable?Sid.
>
>RG-223 is quite usable but will have more loss than RG-400
>type cables.

Actually, according to 
, RG-400 has slightly 
higher loss than RG-223.  I would've guessed otherwise, but there it is in 
B/W.  Given that, I'd prefer RG-223 over the teflon insulated coax due to 
its better flexibility.

RG-400 does have substantially higher power handling capability, slightly 
higher loss notwithstanding.  Probably due to either higher dielectric 
breakdown voltage or higher max. operating temperature.  So if you're 
feeding a very high power out of an amp, you'll need RG-400.

Bob NO6B

RE: [Repeater-Builder] Re: Coax length, etc.

[Gary Schafer]

Hi Allan,

 

Do we really care what the output impedance of the transmitter is? Most
transmitters do not present a pure 50 ohm output but are tuned to transfer
maximum power into a 50 ohm load. This often comes out to something way
different than a 50 ohm source impedance.

As the source impedance does not affect SWR the system doesn't care what it
is as long as the transmitter can transfer maximum power into 50 ohms.

 

What the transmitter does sometimes care about is the reflected impedance
from the first cavity (being hi Q) that is not on frequency. This presents a
highly reactive load to the transmitter that can sometimes cause the
transmitter to overheat or reduce output. Placing a cable of a different
length between output and the first cavity can sometimes change the unwanted
off frequency load seen by the transmitter.

 

73

Gary  K4FMX

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of allan crites
Sent: Friday, August 13, 2010 12:56 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Coax length, etc.

 






Nate,

I have both the 12th and 14th edition of the ARRL Antenna books, the 12th I
acquired in 1974 and have read and re-read the section on transmission lines
and impedance matching probabily more than anyone else has. I sometimes
learn new things with each re-reading, as there is much to be learned.

In my discussions with Kevin Custer about the length of the transmission
line connecting the xmtr output and the input to the duplexer, he suggested
and I accepted, to colaborate on an article explaining the problems
associated with matching the output impedance of a solid state transmitter
of somewhat different than the normal 50 Ohms, and the attempts made by a
manufacturer of duplexers to adapt (read match) the xmtr output via certain
lengths of transmission line and readjustment of the tuning of the cavity
closest to the xmtr output to effect this matching,  ignoring the possible
degradation resulting to the pass and notch characteristics.  

The transmitter in our discussions was the HB GE Mastr 2 which, in the
information available to me, appears to be having an output source impedance
of 35+ or - (some unknown) reactance Ohms.

Kevin commented that it appears that many hams are unaware of, or understand
the methods needed, to do an appropriate job of impedance matching.
Therefor we will be making this article for the benefit of those who don't
understand the impedance matching necessary for optimum power transfer with
a simple to understand way of impedance matching without the use of the
infamous Smith Chart (which I have utilized for the past 50 yrs in all my
impedance matching solutions and cannot be without).

I agree that much information for impedance matching is contained in the
ARRL Antenna Book but in my experience, real life adaptation of this
information is and can be difficult to many hams.

There is also another book I rely on and recommend, which is  "Electronic
Applications of the Smith Chart" by Philip Smith.

Now, if you would like to contribute to our efforts I would gladly accept
your contributions.

Thanks for your input.

Allan Crites  wa9zzu

 

  _  

From: Sid 
To: Repeater-Builder@yahoogroups.com
Sent: Fri, August 13, 2010 10:38:25 AM
Subject: [Repeater-Builder] Re: Coax length, etc.

  

I have a note in my file that I do not recall where it came from relative to
cable length between the duplexer and the TX or between the duplexer and
additional filter. Length = (30)(32.785)(vf/freq).
30 is for 30 degrees, vf is velocity factor, freq is the average of the pass
and reject frequencies. If too short add 180 degrees. Don't know if this is
good info or not. The article would be appreciated. Sid. 


--- In Repeater-Builder@yahoogroups.com
 , Nate Duehr  wrote:
>
> 
> On Aug 5, 2010, at 11:20 AM, Kevin Custer wrote:
> 
> > Allan Crites and I are currently in discussion which will be used as the
basis of a RB web article that will explain exactly what is happening, why
it happens, and why an 'optimized' cable length can be used to transfer
power ending up with the stated loss of the duplexer and have little
reflected power toward the transmitter - so long as the duplexer is tuned
properly and exhibits good return loss on the frequency it's designed to
pass.
> 
> There's already a great book on that topic, it's called the ARRL Antenna
Handbook, and the chapter on transmission lines covers it in more detail
than anyone will ever need to know in the real-world, who's not a practicing
RF Engineer. 
> 
> That book if read cover-to-cover, is also damn good for insomnia. Or at
least it'll keep you distracted while you can't sleep! :-)
> 
> --
> Nate Duehr
> n...@...
> 
> facebook.com/denverpilot
> twitter.com/denverpilot
>

Re: [Repeater-Builder] Re: Coax length, etc.

[allan crites]

Nate,
I have both the 12th and 14th edition of the ARRL Antenna books, the 12th I 
acquired in 1974 and have read and re-read the section on transmission lines 
and 
impedance matching probabily more than anyone else has. I sometimes learn new 
things with each re-reading, as there is much to be learned.
In my discussions with Kevin Custer about the length of the transmission line 
connecting the xmtr output and the input to the duplexer, he suggested and I 
accepted, to colaborate on an article explaining the problems associated with 
matching the output impedance of a solid state transmitter of somewhat 
different 
than the normal 50 Ohms, and the attempts made by a manufacturer of duplexers 
to 
adapt (read match) the xmtr output via certain lengths of transmission line and 
readjustment of the tuning of the cavity closest to the xmtr output to effect 
this matching,  ignoring the possible degradation resulting to the pass and 
notch characteristics.  
The transmitter in our discussions was the HB GE Mastr 2 which, in the 
information available to me, appears to be having an output source impedance of 
35+ or - (some unknown) reactance Ohms.
Kevin commented that it appears that many hams are unaware of, or understand 
the 
methods needed, to do an appropriate job of impedance matching.
Therefor we will be making this article for the benefit of those who don't 
understand the impedance matching necessary for optimum power transfer with a 
simple to understand way of impedance matching without the use of the 
infamous Smith Chart (which I have utilized for the past 50 yrs in all my 
impedance matching solutions and cannot be without).
I agree that much information for impedance matching is contained in the ARRL 
Antenna Book but in my experience, real life adaptation of this information is 
and can be difficult to many hams.
There is also another book I rely on and recommend, which is  "Electronic 
Applications of the Smith Chart" by Philip Smith.
Now, if you would like to contribute to our efforts I would gladly accept your 
contributions.
Thanks for your input.
Allan Crites  wa9zzu




From: Sid 
To: Repeater-Builder@yahoogroups.com
Sent: Fri, August 13, 2010 10:38:25 AM
Subject: [Repeater-Builder] Re: Coax length, etc.

  
I have a note in my file that I do not recall where it came from relative to 
cable length between the duplexer and the TX or between the duplexer and 
additional filter. Length = (30)(32.785)(vf/freq).
30 is for 30 degrees, vf is velocity factor, freq is the average of the pass 
and 
reject frequencies. If too short add 180 degrees. Don't know if this is good 
info or not. The article would be appreciated. Sid. 



--- In Repeater-Builder@yahoogroups.com, Nate Duehr  wrote:
>
> 
> On Aug 5, 2010, at 11:20 AM, Kevin Custer wrote:
> 
> > Allan Crites and I are currently in discussion which will be used as the 
>basis of a RB web article that will explain exactly what is happening, why it 
>happens, and why an 'optimized' cable length can be used to transfer power 
>ending up with the stated loss of the duplexer and have little reflected power 
>toward the transmitter - so long as the duplexer is tuned properly and 
>exhibits 
>good return loss on the frequency it's designed to pass.
> 
> There's already a great book on that topic, it's called the ARRL Antenna 
>Handbook, and the chapter on transmission lines covers it in more detail than 
>anyone will ever need to know in the real-world, who's not a practicing RF 
>Engineer. 
>
> 
> That book if read cover-to-cover, is also damn good for insomnia. Or at least 
>it'll keep you distracted while you can't sleep! :-)
> 
> --
> Nate Duehr
> n...@...
> 
> facebook.com/denverpilot
> twitter.com/denverpilot
>

Re: [Repeater-Builder] Re: Coax length, etc.

[Russ Hines]

 Hmm, the formula is a bit off, but... 30 x 32.785 = 983.55.  I'll also 
bet length is expressed in feet.


Looks eerily like someone wants you to cut a one-wavelength piece of 
coax cut at the mean repeater frequency.


Just a guess.

73, Russ WB8ZCC

On 8/13/2010 11:38 AM, Sid wrote:


I have a note in my file that I do not recall where it came from 
relative to cable length between the duplexer and the TX or between 
the duplexer and additional filter. Length = (30)(32.785)(vf/freq).
30 is for 30 degrees, vf is velocity factor, freq is the average of 
the pass and reject frequencies. If too short add 180 degrees. Don't 
know if this is good info or not. The article would be appreciated. Sid.



--- In Repeater-Builder@yahoogroups.com 
, Nate Duehr  wrote:

>
>
> On Aug 5, 2010, at 11:20 AM, Kevin Custer wrote:
>
> > Allan Crites and I are currently in discussion which will be used 
as the basis of a RB web article that will explain exactly what is 
happening, why it happens, and why an 'optimized' cable length can be 
used to transfer power ending up with the stated loss of the duplexer 
and have little reflected power toward the transmitter - so long as 
the duplexer is tuned properly and exhibits good return loss on the 
frequency it's designed to pass.

>
> There's already a great book on that topic, it's called the ARRL 
Antenna Handbook, and the chapter on transmission lines covers it in 
more detail than anyone will ever need to know in the real-world, 
who's not a practicing RF Engineer.

>
> That book if read cover-to-cover, is also damn good for insomnia. Or 
at least it'll keep you distracted while you can't sleep! :-)

>
> --
> Nate Duehr
> n...@...
>
> facebook.com/denverpilot
> twitter.com/denverpilot
>

Re: [Repeater-Builder] Tait T800 Series II

[Steve]

Hi
the T800,s both series one and two are great, series one uses eproms
series two is an eeprom programmed using a single data line via an rj11
skt on the front and rear. In the UK a series two sells for around 400ukp
a low band series one for around 200ukp.

73

Steve
- Original Message - 
From: "Ken Arck" 
To: 
Sent: Friday, August 13, 2010 5:48 PM
Subject: [Repeater-Builder] Tait T800 Series II


> The last time I delt with Tait equipment was their mobiles back in
> the early 90's. They worked well and were rugged (installed in
> helicopters so you know there was lots of vibration!).
>
> Anyway, consider the following:
>
> Tait T800 Series II Repeater UHF 440-480
>
> 100W
>
> Consists of:
> T808-10-0012 110 VAC 20A switching power supply
> T859-20-0005 UHF 100W power amplifier
> T857-26-0200 UHF Exciter, 440-480 MHz
> T855-20-0200 UHF Receiver, 440-480 MHz
> T800-22- Series II rack frame
> T800 Series II analog backplane
> T800 Series II speaker panel
>
> Any comments on the reliability, performance and OF COURSE, what's a
> fair price for the above?
>
> 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
>
>
>

[Repeater-Builder] Tait T800 Series II

[Ken Arck]

The last time I delt with Tait equipment was their mobiles back in 
the early 90's. They worked well and were rugged (installed in 
helicopters so you know there was lots of vibration!).

Anyway, consider the following:

Tait T800 Series II Repeater UHF 440-480

100W

Consists of:
T808-10-0012 110 VAC 20A switching power supply
T859-20-0005 UHF 100W power amplifier
T857-26-0200 UHF Exciter, 440-480 MHz
T855-20-0200 UHF Receiver, 440-480 MHz
T800-22- Series II rack frame
T800 Series II analog backplane
T800 Series II speaker panel

Any comments on the reliability, performance and OF COURSE, what's a 
fair price for the above?

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] Re: Mystery Micor problem

[La Rue Communications]

If it wasnt Friday the 13th and I wasnt a bonehead and left my shop keys at 
home - I would check our stash for you. Can you wait til MOnday and I will?

John Hymes
La Rue Communications
10 S. Aurora Street
Stockton, CA 95202
http://tinyurl.com/2dtngmn
  - Original Message - 
  From: n3ssl 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, August 13, 2010 8:08 AM
  Subject: [Repeater-Builder] Re: Mystery Micor problem



  Glenn and Group,

  You were right on the channel elment being the issue ( placed a kxn 1024 for 
uhf and right on Rx.) Now i am looking for a KXN 1019 VHF not finding any in 
boxes or ebay. anyone have one they can spare?

  Ryan n3ssl 

  --- In Repeater-Builder@yahoogroups.com, Glenn Little WB4UIV 
 wrote:
  >
  > If you have another channel element that has a crystal, I would use 
  > it to determine if the problem is in the radio or the element.
  > I suspect that the bad capacitor is in the element.
  > 
  > What is the part number of the channel element?
  > 
  > 73
  > Glenn
  > WB4UIV
  > 
  > At 10:03 PM 8/9/2010, you wrote:
  > >Glenn,
  > >Is it safe to say look in the channel element for the bad cap ?
  > >Tempeture is not a issue with this unit it was in a heated and A/C 
  > >garage kept about 65-80 degrees with dehumdifer. I am glad the new 
  > >site is climate controlled also.
  > >
  > >Ryan n3ssl
  > >
  > >--- In Repeater-Builder@yahoogroups.com, Glenn Little WB4UIV 
  > > wrote:
  > > >
  > > > We had this problem in Johnson radios.
  > > > What it turned out to be was a plate of a silver mica capacitor
  > > > coming disconnected internally in the capacitor.
  > > > This caused the capacitor to shift to a lower capacitance by the
  > > > amount that the plate contributed to the capacitor.
  > > > The lower capacitance caused the radio frequency to shift high and
  > > > outside the tuning range of the netting device.
  > > > I cannot tell you what capacitor has failed.
  > > > Check the silver mica capacitors in the tuning circuit and replace
  > > > the one that is low in value.
  > > >
  > > > I also have not been in a Micor element in many years.
  > > >
  > > > Hope this helps.
  > > > This appears to be a somewhat common failure for silver mica
  > > > capacitor due to the way the capacitor is physically constructed.
  > > >
  > > > 73
  > > > Glenn
  > > > WB4UIV
  > > >
  > > >
  > > > At 09:09 PM 8/8/2010, you wrote:
  > > > >Glenn, OZ and group
  > > > >
  > > > >Its a step jump 5 khz up and get - 200 hz of crystal movment. What
  > > > >silver mica Cap is it? I have not looked inside a channel element in
  > > > >years usally send them out and trust the mfg.
  > > > >
  > > > >I also gave the crystal movement a thought but was is a temp
  > > > >controlled enviroment.
  > > > >
  > > > >Ryan
  > > > >
  > > > >--- In Repeater-Builder@yahoogroups.com, Glenn Little WB4UIV
  > > > > wrote:
  > > > > >
  > > > > > Was the shift a drift or a step jump?
  > > > > >
  > > > > > If a step jump, you probably have a bad silver mica capacitor.
  > > > > >
  > > > > > 73
  > > > > > Glenn
  > > > > > WB4UIV
  > > > > >
  > > > > > At 04:23 PM 8/8/2010, you wrote:
  > > > > > >Hi Group,
  > > > > > >
  > > > > > >I have a Micor mobile set up as repeater. Worked great and was on
  > > > > > >frequency for over 8 years no problems.(lost rpt site May 2010) and
  > > > > > >have a new site to get on.The problem i am having is the TX drifted
  > > > > > >5 khz up on TX from 145.310 to 145.315. I get plenty of deviation
  > > > > > >and audio drive and 9.6 v to crystal element. I am not having any
  > > > > > >luck messing with Netting adjustment i get -200 hz max. I also have
  > > > > > >a UHF Rx unit for control installed and it is 10khz low on 
frequency.
  > > > > > >
  > > > > > >
  > > > > > >The 144.710 RX crystal is right on the money for specs. Very odd
  > > > > > >situation. anyone have ideas where to check or a fluke the crystals
  > > > > > >are both bad.
  > > > > > >
  > > > > > >Ryan n3ssl
  > > > > > >
  > > > > > >
  > > > > > >
  > > > > > >
  > > > > > >
  > > > > > >
  > > > > > >
  > > > > > >Yahoo! Groups Links
  > > > > > >
  > > > > > >
  > > > > > >
  > > > > >
  > > > >
  > > > >
  > > > >
  > > > >
  > > > >
  > > > >
  > > > >
  > > > >
  > > > >Yahoo! Groups Links
  > > > >
  > > > >
  > > > >
  > > >
  > >
  > >
  > >
  > >
  > >
  > >
  > >
  > >
  > >Yahoo! Groups Links
  > >
  > >
  > >
  >



  

[Repeater-Builder] Re: Coax length, etc.

[Sid]

I have a note in my file that I do not recall where it came from relative to 
cable length between the duplexer and the TX or between the duplexer and 
additional filter.  Length = (30)(32.785)(vf/freq).
30 is for 30 degrees, vf is velocity factor, freq is the average of the pass 
and reject frequencies.  If too short add 180 degrees. Don't know if this is 
good info or not. The article would be appreciated.  Sid. 
 

--- In Repeater-Builder@yahoogroups.com, Nate Duehr  wrote:
>
> 
> On Aug 5, 2010, at 11:20 AM, Kevin Custer wrote:
> 
> > Allan Crites and I are currently in discussion which will be used as the 
> > basis of a RB web article that will explain exactly what is happening, why 
> > it happens, and why an 'optimized' cable length can be used to transfer 
> > power ending up with the stated loss of the duplexer and have little 
> > reflected power toward the transmitter - so long as the duplexer is tuned 
> > properly and exhibits good return loss on the frequency it's designed to 
> > pass.
> 
> There's already a great book on that topic, it's called the ARRL Antenna 
> Handbook, and the chapter on transmission lines covers it in more detail than 
> anyone will ever need to know in the real-world, who's not a practicing RF 
> Engineer. 
> 
> That book if read cover-to-cover, is also damn good for insomnia. Or at least 
> it'll keep you distracted while you can't sleep! :-)
> 
> --
> Nate Duehr
> n...@...
> 
> facebook.com/denverpilot
> twitter.com/denverpilot
>

[Repeater-Builder] Re: Mystery Micor problem

[n3ssl]

Glenn and Group,

You were right on the channel elment being the issue ( placed a kxn 1024 for 
uhf and right on Rx.)  Now i am looking for a KXN 1019 VHF not finding any in 
boxes or ebay. anyone have one they can spare?

Ryan n3ssl 

--- In Repeater-Builder@yahoogroups.com, Glenn Little WB4UIV 
 wrote:
>
> If you have another channel element that has a crystal, I would use 
> it to determine if the problem is in the radio or the element.
> I suspect that the bad capacitor is in the element.
> 
> What is the part number of the channel element?
> 
> 73
> Glenn
> WB4UIV
> 
> At 10:03 PM 8/9/2010, you wrote:
> >Glenn,
> >Is it safe to say look in the channel element for the bad cap ?
> >Tempeture is not a issue with this unit it was in a heated and A/C 
> >garage kept about 65-80 degrees with dehumdifer. I am glad the new 
> >site is climate controlled also.
> >
> >Ryan n3ssl
> >
> >--- In Repeater-Builder@yahoogroups.com, Glenn Little WB4UIV 
> > wrote:
> > >
> > > We had this problem in Johnson radios.
> > > What it turned out to be was a plate of a silver mica capacitor
> > > coming disconnected internally in the capacitor.
> > > This caused the capacitor to shift to a lower capacitance by the
> > > amount that the plate contributed to the capacitor.
> > > The lower capacitance caused the radio frequency to shift high and
> > > outside the tuning range of the netting device.
> > > I cannot tell you what capacitor has failed.
> > > Check the silver mica capacitors in the tuning circuit and replace
> > > the one that is low in value.
> > >
> > > I also have not been in a Micor element in many years.
> > >
> > > Hope this helps.
> > > This appears to be a somewhat common failure for silver mica
> > > capacitor due to the way the capacitor is physically constructed.
> > >
> > > 73
> > > Glenn
> > > WB4UIV
> > >
> > >
> > > At 09:09 PM 8/8/2010, you wrote:
> > > >Glenn, OZ and group
> > > >
> > > >Its a step jump 5 khz up and get - 200 hz of crystal movment. What
> > > >silver mica Cap is it? I have not looked inside a channel element in
> > > >years usally send them out and trust the mfg.
> > > >
> > > >I also gave the crystal movement a thought but was is a temp
> > > >controlled enviroment.
> > > >
> > > >Ryan
> > > >
> > > >--- In Repeater-Builder@yahoogroups.com, Glenn Little WB4UIV
> > > > wrote:
> > > > >
> > > > > Was the shift a drift or a step jump?
> > > > >
> > > > > If a step jump, you probably have a bad silver mica capacitor.
> > > > >
> > > > > 73
> > > > > Glenn
> > > > > WB4UIV
> > > > >
> > > > > At 04:23 PM 8/8/2010, you wrote:
> > > > > >Hi Group,
> > > > > >
> > > > > >I have a Micor mobile set up as repeater. Worked great and was on
> > > > > >frequency for over 8 years no problems.(lost rpt site May 2010) and
> > > > > >have a new site to get on.The problem i am having is the TX drifted
> > > > > >5 khz up on TX from 145.310 to 145.315. I get plenty of deviation
> > > > > >and audio drive and 9.6 v to crystal element. I am not having any
> > > > > >luck messing with Netting adjustment i get -200 hz max. I also have
> > > > > >a UHF Rx unit for control installed and it is 10khz low on frequency.
> > > > > >
> > > > > >
> > > > > >The 144.710 RX crystal is right on the money for specs. Very odd
> > > > > >situation. anyone have ideas where to check or a fluke the crystals
> > > > > >are both bad.
> > > > > >
> > > > > >Ryan n3ssl
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >Yahoo! Groups Links
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >Yahoo! Groups Links
> > > >
> > > >
> > > >
> > >
> >
> >
> >
> >
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
>

Re: [Repeater-Builder] OT: Licensing Exam Info

[Mark Tomany]

Well if you think about it, Nate, VE's ARE an off-site testing facillity... of 
sorts.
 
Mark - N9WYS (also a pilot)

--- On Thu, 8/12/10, Nate Duehr  wrote:


Side-comment: As a pilot and IT person, I've been taking tests for both at 
professional testing locations like ProMetric now for at least a decade.  

With the removal of the Code, I've always wondered why the FCC hasn't gone the 
way the FAA did, and dropped the need for the VE's altogether.  Just send 
people to the various "testing centers" around the world, and be done with it.

Even most of my other volunteer organizations have moved the majority of their 
testing online (to their own websites, but those are open-book tests... so no 
need to have a test proctor, like the professional testing facilities have, and 
video cameras recording you).

--
Nate Duehr
n...@natetech.com

Re: [Repeater-Builder] Re: Dielectric diplexer

[Kris Kirby]

On Thu, 12 Aug 2010, skipp025 wrote:
> > brand diplexer rated at 25000 watts on 191 Mhz from a analog TV 
> > station.  I feel a little bit like the dog that catches the car he 
> > is chasing.  Now that I have it, what can I do with it?  Any ideas?  
> > Can it go to 220? Does anyone have any experience with these? Thanks 
> > Bill N4XIR
> 
> I'm thinking duplexer and/or cavities for any of the VHF and some UHF 
> Bands if you do the proper homework.

Even getting it cut down and welded back together, you could easily to 
420-450MHz, perfect for that 421MHz 1.5kW ATV machine you're building. 

220... oh but the cans must have a high Q

--
Kris Kirby, KE4AHR
Disinformation Analyst

Re: Re: [Repeater-Builder] Re: OT: Licensing Exam Info

[dmurman]

Having VE's is the best for HAM RADIO. When I was first licensed I lived at Ft 
Richardson and had to go to Anchorage to take the test. When I upgraded I was 
in Pensylvania at Tobyhanna and the closest examination location was 
Philidelphia. At least with the VEs they are in your comunity and you don't 
have to traver MILES to take a test.
 
 
David


Aug 13, 2010 12:45:02 PM, Repeater-Builder@yahoogroups.com wrote:

> 
> 



The other potential problem would be where the test centers are located. I 
> went to the site, but didn't find site locations. Maybe you get to a 
> location after you keep drilling down on a particular test, but I only went 
>
> a few screens in.
> 
> Anyway, the VE's are all over the place. The test centers could involve 
> considerable drive time - not a good thing when you are trying to encourage 
>
> someone to get a license.
> 
> Chuck
> WB2EDV
> 
> - Original Message - 
> From: "lenaw12" 
> To: 
> Sent: Thursday, August 12, 2010 11:54 PM
> Subject: [Repeater-Builder] Re: OT: Licensing Exam Info
> 
> > Be careful what you wish for...a Ham license has "no value" 
>so the VE's 
> > can only charge their "actual expenses" for administering the 
>test...here 
> > in the east it is around $15...ProMetric probably wouldn't let you walk 
>in 
> > the door for $15.
> >
> > The FCC is no longer in the "exam business" so it doesn't want 
>to spend 
> > any money developing tests, keeping them current, administering them or 
>
> > "certifying" the testers...Ham Radio is a "self policed" 
>holder of 
> > valuable spectrum...by administering their own exams, hams are showing 
>the 
> > responsibility exists to have the privilege of holding RF spectrum.
> >
> > I just went to the ProMetric site
> > http://www.register.prometric.com/Index.asp
> >
> > and ran through some of the pricing, the Microsoft tests are $60 and the 
>
> > SunSystems are $500
> >
> > I appreciate our VE's (and they flunked me on my last unstudied, dry run 
>
> > at Extra)
> >
> > LW
> >
> > --- In Repeater-Builder@yahoogroups.com, Nate Duehr wrote:
> >>
> >> Side-comment: As a pilot and IT person, I've been taking tests for 
>both 
> >> at professional testing locations like ProMetric now for at least 
>a 
> >> decade.
> >>
> >> With the removal of the Code, I've always wondered why the FCC hasn't 
>
> >> gone the way the FAA did, and dropped the need for the VE's altogether. 
>
> >> Just send people to the various "testing centers" around 
>the world, and 
> >> be done with it.
> >>
> >> Even most of my other volunteer organizations have moved the majority 
>of 
> >> their testing online (to their own websites, but those are open-book 
>
> >> tests... so no need to have a test proctor, like the professional 
>testing 
> >> facilities have, and video cameras recording you).
> >>
> >> --
> >> Nate Duehr
> >> n...@...
> >>
> >> facebook.com/denverpilot
> >> twitter.com/denverpilot
> 
> 

Re: [Repeater-Builder] Re: OT: Licensing Exam Info

[Chuck Kelsey]

The other potential problem would be where the test centers are located. I 
went to the site, but didn't find site locations. Maybe you get to a 
location after you keep drilling down on a particular test, but I only went 
a few screens in.

Anyway, the VE's are all over the place. The test centers could involve 
considerable drive time - not a good thing when you are trying to encourage 
someone to get a license.

Chuck
WB2EDV



- Original Message - 
From: "lenaw12" 
To: 
Sent: Thursday, August 12, 2010 11:54 PM
Subject: [Repeater-Builder] Re: OT: Licensing Exam Info


> Be careful what you wish for...a Ham license has "no value" so the VE's 
> can only charge their "actual expenses" for administering the test...here 
> in the east it is around $15...ProMetric probably wouldn't let you walk in 
> the door for $15.
>
> The FCC is no longer in the "exam business" so it doesn't want to spend 
> any money developing tests, keeping them current, administering them or 
> "certifying" the testers...Ham Radio is a "self policed" holder of 
> valuable spectrum...by administering their own exams, hams are showing the 
> responsibility exists to have the privilege of holding RF spectrum.
>
> I just went to the ProMetric site
> http://www.register.prometric.com/Index.asp
>
> and ran through some of the pricing, the Microsoft tests are $60 and the 
> SunSystems are $500
>
> I appreciate our VE's (and they flunked me on my last unstudied, dry run 
> at Extra)
>
> LW
>
> --- In Repeater-Builder@yahoogroups.com, Nate Duehr  wrote:
>>
>> Side-comment: As a pilot and IT person, I've been taking tests for both 
>> at professional testing locations like ProMetric now for at least a 
>> decade.
>>
>> With the removal of the Code, I've always wondered why the FCC hasn't 
>> gone the way the FAA did, and dropped the need for the VE's altogether. 
>> Just send people to the various "testing centers" around the world, and 
>> be done with it.
>>
>> Even most of my other volunteer organizations have moved the majority of 
>> their testing online (to their own websites, but those are open-book 
>> tests... so no need to have a test proctor, like the professional testing 
>> facilities have, and video cameras recording you).
>>
>> --
>> Nate Duehr
>> n...@...
>>
>> facebook.com/denverpilot
>> twitter.com/denverpilot

Re: [Repeater-Builder] Re: Tait T296

[Gareth Bennett]

Hi Gordon, 
Yep, I can remember installing new T300's at the NZPO and now de-commissioning 
them a few decades later.
They are pretty straightforward and still have a good following and many are 
still in active service.
What do you wish to accomplish? If you want to utilise them as a basic 2 meter 
repeater, no problems as you can set up the radios as a basic talk through 
repeater.

What versions do you have, the /02 probably were the most common and the /01 
were made for exclusive NZPO use (BNC test ports on the front for LO alignment).
I'm guessing that if they came out of emergency service use, they more than 
likely were on the old CD band of around 149 MHz @ 25 KHz, so would need 
minimal re-alignment for amateur use.

I've got The manuals somewhere on PDF if you require them.


Gareth Bennett

RadioSystems Limited
P.O. Box 5202
Dunedin  9024
New Zealand
 
DDI:   (03) 489 1101
FAX:   (03) 489 1151
MOB: (0224) 588 377

gare...@radsys.co.nz


  - Original Message - 
  From: Gordon Cooper 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, August 13, 2010 7:46 PM
  Subject: Re: [Repeater-Builder] Re: Tait T296



  On 13/08/10 19:16, Gareth Bennett wrote: 

  

Sounds like you have a  pair of T355 T356 radios,

You may well want to open up the TX PA unit (Behind the alloy shield) and 
change the electrolytics in there as well as this area
  is a well known area of trouble and can cause no end of  spuries. 
Just ensure that you replace the caps with 105 deg C varients and you 
should be fine and give you another 20 years of service :-)


 Thanks Gareth,
  Tait equipment is fairly new to me - even 
though I passed their
  Christchurch factory every day (some 40 years ago) on the way to work. Most 
of my 
  'fixit' time was spent on Collins, Wilcox, and yes, Collier & Beale 
transmitters, plus 
  Cossor & Marconi radars.

What I have here is two pairs of T355 T356 VHFs. A pair of similar UHF 
equipment, 
  along with an AWA 70 cm duplexer and a very interesting 150 MHz duplexer made 
  in Finland. Regrettably, someone has cannibalised the rack wiring with 
sidecutters
  so it is a rewire and make a new monitor panel.

  Many thanks,
  Gordon.



  

[Repeater-Builder] Re: Tait T296

[niteviser]

Hi Mike,

I have accumulated a fair bit of knowledge over the years and I can find a 
reasonable amount of info, if that is what you are asking. I 'listen in' here 
and on the Tait group.

niteviser

--- In Repeater-Builder@yahoogroups.com, Mike Morris  wrote:
>
> I converted it and added the PDF (and the JPG) to the Tait page at 
> repeater-builder.
> 
> Are there any Tait experts in the 4800+ members of this group?
> 
> Mike WA6ILQ
> 
> At 10:20 PM 08/12/10, you wrote:
> >Gordon,
> >
> >I gave trying to make a pdf out of it. I have uploaded the jpg image 
> >to the files section, see how you go with that.
> >
> >niteviser
> >
> >--- In Repeater-Builder@yahoogroups.com, Gordon Cooper  wrote:
> > >
> > > Thanks Gareth.  I was going to replace the electro's, and a
> > > current rating of 6A is more reasonable with only a single
> > > pass transistor.
> > >
> > > As you have probably guessed, this equipment is T300 series
> > > but my surprise is that it has hardly been used. Set up as a
> > > base station for CD and has lived its life in a cupboard as a
> > > backup.
> > >
> > > Cheers,
> > > Gordon Tauranga Emergency Communications Group.
> > >
> >
> >
> >
> >
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
>

Re: [Repeater-Builder] Re: Tait T296

[Gordon Cooper]

On 13/08/10 19:16, Gareth Bennett wrote:


Sounds like you have a  pair of T355 T356 radios,
You may well want to open up the TX PA unit (Behind the alloy 
shield) and change the electrolytics in there as well as this area

is a well known area of trouble and can cause no end of  spuries.
Just ensure that you replace the caps with 105 deg C varients and you 
should be fine and give you another 20 years of service :-)



   Thanks Gareth,
Tait equipment is fairly new to me - 
even though I passed their
Christchurch factory every day (some 40 years ago) on the way to work. 
Most of my
'fixit' time was spent on Collins, Wilcox, and yes, Collier & Beale 
transmitters, plus

Cossor & Marconi radars.

  What I have here is two pairs of T355 T356 VHFs. A pair of similar 
UHF equipment,
along with an AWA 70 cm duplexer and a very interesting 150 MHz duplexer 
made
in Finland. Regrettably, someone has cannibalised the rack wiring with 
sidecutters

so it is a rewire and make a new monitor panel.

Many thanks,
Gordon.

Re: [Repeater-Builder] Re: Tait T296

[Gareth Bennett]

Hi Gordon,
Sounds like you have a  pair of T355 T356 radios,

You may well want to open up the TX PA unit (Behind the alloy shield) and 
change the electrolytics in there as well as this area is a well known area of 
trouble and can cause no end of  spuries.
Just ensure that you replace the caps with 105 deg C varients and you should be 
fine and give you another 20 years of service :-)

Cheers

Gareth Bennett

RadioSystems Limited
P.O. Box 5202
Dunedin  9024
New Zealand
 
DDI:   (03) 489 1101
FAX:   (03) 489 1151
MOB: (0224) 588 377

gare...@radsys.co.nz


  - Original Message - 
  From: Gordon Cooper 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, August 13, 2010 2:17 PM
  Subject: [Repeater-Builder] Re: Tait T296



  Thanks Gareth. I was going to replace the electro's, and a
  current rating of 6A is more reasonable with only a single
  pass transistor.

  As you have probably guessed, this equipment is T300 series
  but my surprise is that it has hardly been used. Set up as a
  base station for CD and has lived its life in a cupboard as a
  backup.

  Cheers,
  Gordon Tauranga Emergency Communications Group.


  

Re: [Repeater-Builder] Re: Tait T296

[Gareth Bennett]

Hi Mike,
Depends on what you want to know I suppose?


Gareth Bennett

RadioSystems Limited
P.O. Box 5202
Dunedin  9024
New Zealand
 
DDI:   (03) 489 1101
FAX:   (03) 489 1151
MOB: (0224) 588 377

gare...@radsys.co.nz


  - Original Message - 
  From: Mike Morris 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, August 13, 2010 7:01 PM
  Subject: Re: [Repeater-Builder] Re: Tait T296



  I converted it and added the PDF (and the JPG) to the Tait page at 
  repeater-builder.

  Are there any Tait experts in the 4800+ members of this group?

  Mike WA6ILQ

  At 10:20 PM 08/12/10, you wrote:
  >Gordon,
  >
  >I gave trying to make a pdf out of it. I have uploaded the jpg image 
  >to the files section, see how you go with that.
  >
  >niteviser
  >
  >--- In Repeater-Builder@yahoogroups.com, Gordon Cooper  wrote:
  > >
  > > Thanks Gareth. I was going to replace the electro's, and a
  > > current rating of 6A is more reasonable with only a single
  > > pass transistor.
  > >
  > > As you have probably guessed, this equipment is T300 series
  > > but my surprise is that it has hardly been used. Set up as a
  > > base station for CD and has lived its life in a cupboard as a
  > > backup.
  > >
  > > Cheers,
  > > Gordon Tauranga Emergency Communications Group.
  > >
  >
  >
  >
  >
  >
  >
  >
  >
  >Yahoo! Groups Links
  >
  >
  >


  

Re: [Repeater-Builder] Re: Tait T296

[Mike Morris]

I converted it and added the PDF (and the JPG) to the Tait page at 
repeater-builder.

Are there any Tait experts in the 4800+ members of this group?

Mike WA6ILQ

At 10:20 PM 08/12/10, you wrote:
>Gordon,
>
>I gave trying to make a pdf out of it. I have uploaded the jpg image 
>to the files section, see how you go with that.
>
>niteviser
>
>--- In Repeater-Builder@yahoogroups.com, Gordon Cooper  wrote:
> >
> > Thanks Gareth.  I was going to replace the electro's, and a
> > current rating of 6A is more reasonable with only a single
> > pass transistor.
> >
> > As you have probably guessed, this equipment is T300 series
> > but my surprise is that it has hardly been used. Set up as a
> > base station for CD and has lived its life in a cupboard as a
> > backup.
> >
> > Cheers,
> > Gordon Tauranga Emergency Communications Group.
> >
>
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>