Re: [Repeater-Builder] 220 repeater receiver recommendations?

[n8oku]

hamtronics...  been using them for 15 years...  they are the only  choice 
here...   allen...   ac8dx
** AOL now offers free 
email to everyone.  Find out more about what's free from AOL at 
http://www.aol.com.

RE: [Repeater-Builder] Re: Johnson PPL 6060 manual needed

[Paul Finch]

Mike,
 
Durn it Mike, you let the cat out of the bag!  I feel the price of the old
radios going up now!  Good thing about it?  I have 5 brand new in the box
PPL 6060's to work with plus several used ones!
 
Paul
 
 
 

   _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Mike - W5JR (f/k/a
N5FL)
Sent: Thursday, February 22, 2007 10:01 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Johnson PPL 6060 manual needed






Posted by: "JOHN MACKEY" HYPERLINK "mailto:[EMAIL PROTECTED]
Re%3A%20Johnson%20PPL%206060%20manual%20needed"[EMAIL PROTECTED]   HYPERLINK
"http://profiles.yahoo.com/jmackey_usa_net"jmackey_usa_net 





Wed Feb 21, 2007 8:26 pm (PST) 



are you saying a 45-470 MHz PPL6060 will work in the 420 MHz range?


Absolutely!!  I've moved many an EFJ to 420 operation - 558, 559, 6060.  And
some of them began life as T-Band units, 470-512 MHz.  In the RX, use high
side injection xtals.  Matter of fact, use your existing 440 or 450 xtals to
test with.  The radio will hear a signal -21.4 MHz lower than your current
freq.  You may have to add a 1/4 turn to each coil in the multiplier
helical.  In the front end, use a 1/4 turn for 427-433 range and a half turn
for the low end.  We used regular house wire, 10 ga I think for the 558/559
units, formed around the proper sized drill bit.  Tack solder it to the end
of the existing coils.  They tune right up.  Sometimes, 1/4 inch longer
screws is all it takes.  If they are T-Band, use more coil.

On the TX, some padding in parallel with caps in the multipliers is needed
to bring them in range, especially if TX'ing low.  It is easy to get a
doubler acting like a tripler, so be sure to have a spectrum analyzer on
hand to verify what freq the RF is on.  Same is true for the amplifier
stages.  Two of the helicals in the 6060 casting are for TX and may need the
coil extension trick like the RX side.  They make good 420 full duplex link
radios, similar to a modified MVP.

- mike - w5jr 

 


Visit HYPERLINK "http://www.ourazle.com"OurAzle.com
It's free and you can talk about anything in Azle you like! 


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Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In My Area

[Mike Morris WA6ILQ]

Comments in the text.

At 02:49 PM 02/22/07, you wrote:


"Tony L." [EMAIL PROTECTED] wrote…

The number of active ham repeaters in my area is way, way down in
comparison to levels of 10 years ago. It isn't uncommon to monitor a
repeater frequency and hear no traffic for weeks. Some clubs &
individuals have just walked away from coordinated pairs.

However, there are a few repeaters that have remained active, although
certainly not to the extent they were in the past. Interestingly, even
though traffic is way down, there's still a waiting list in my area for
coordinated pairs on all bands.

Questions:

1) Has there been a decline in traffic and the number of active
repeaters in your area?

2) If so, what do you feel the primary cause is?

3) What can be done to generate renewed interest?

Shorty K6JSI answers:

1) Some repeaters yes, our repeaters, no.

2) Cell phones, Ipod, computers, 100s of TV channels, etc.

3) Bring in young people to the hobby.  Make 
your repeater interesting to younger people.  Do 
things they enjoy doing.  Make being on the air more desirable to them.


I own and operate the Western Intertie Network, 
or the WIN System.  We have 44 repeaters linked 
together 24/7, with lots of activity.  We are in 
13 States and Three Countries.  Since 2000 we 
have averaged 60 new members a year (at $120 a year dues).


And no, that's not a typo.  Fourty-four separate repeaters.  Plus the
point-to-point RF links.  Almost all are 100w UHF Mastr IIs, some
are MVPs.  Most of the link radios are MVPs.

Make it interesting and they will come.  You are 
competing with a lot of splashy media out there, 
but nothing is as exciting as good two way 
communications through your own hand held 
radio.  Make the younger generation realize that.


Jeff (Shorty) Stouffer, K6JSI
Home:  760/ 724-4020
Cell:  760/ 716-7033
The WIN System
The American Red Cross
winsystem.org
flataudio.com

Western Intertie Network
www.winsystem.org


That web site above is worth looking over.  Some of the
coverage maps will astound the east coast folks.

One of the things that the groups does is have monthly
breakfasts where everybody is welcome, licensed or not.
For a long time the San Diego breakfast was at a family-
owned restaurant that didn't have breakfast hours - the
normal Saturday hours were 11am to 1am.  Somebody
talked to the owner and convinced him to have a cook
and two waitresses come in at 8am and do a buffet
breakfast just for the WinSystem
a crowd of over 30 folks each month made it worth it.

Another is to have an IRLP reflector nailed up 7x24.
Anybody can punch up reflector 9453 and join in.
Especially for the INSOMNIAC NET...
7 nights a week, 11:00 PM Pacific Time ... Every night
all of Southern California and portions of the known world
via IRLP.
There are regular checkins from Down Under, and Europe.

You can also listen via the streaming audio 
available at 



While 11pm Pacific is probably way to late (early?) for
most of the folks reading this there is no reason that
you couldn't "take a listen" some night with a tape
recorder tied to the Line Out jack on your computer's
sound card (listening to the streamed audio).  Then
play the tape on your way to work...

And the WinSystem and the Insomniac Net welcomes
the scanner folks... I don't check in to that net too often,
maybe 2-4 times a month, but remember hearing the net
control acknowledge the scanner folks that emailed their
answers to the trivia questions to the net control during
the net.
Shorty puts out a regular emailed newsletter and has a
paragraph of text on each new member - I remember
reading that several of them went out and got their tech
class licenses due to just that kind of encouragement.

And in answer to the posed questions, I will state that thirty
years ago several 2m repeaters in this area had PTT times
measured in the 5 to 10 hours per day range, depending on
day of the week.  I'd be very surprised if today they are over
15 hours per month range.  Some have joined interlinked
systems and while their hours may be similar the content
is redundant to other systems... i.e. 5 repeaters with 1/5 the
total users still have the same airtime.

Cellphones are the major cost.  The "entrance fee" to ham
radio is the time to get the license, the effort to learn
something (the technology) that is totally foreign to most
folks (how many adults can actually program a VCR or a
TiVo?) then add the cost of the radios.
A cellphone is a signature on a form and $30 per month.
Plus it's reasonably secure - which a ham radio is definitely
not.

One reason that nobody has mentioned is that the sweetheart
site deals are dying off.  Back in the 60s and 70s, end even into
the early 80s you could get a good site by having one person that
knew a site owner make a phone call.
One of my first sites was acquired that way - a friend made a phone
call and I was allowed

Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In My Area

[Nick Papadonis]

I agree, repeater us is down.  

Maybe features such as Echolink, IRLP or DStar/AMBE digitial voice will 
generate interest?  For instance, with Echolink you can enter in another user's 
callsign and have your repeater "remotely connect" to the other user's one 
(providing your friend has identified with their local repeater).  I.e 
establishing a connection between two repeaters via callsign lookup service.  
While this feature only works using IP address now, it could be applied to work 
with frequency and direction.  I.e. a second digitally controlled frequency 
agile radio connected to the repeater and digitally controlled rotator.  This 
is also an interesting concept.

Nick

- Original Message 
From: Jack Taylor <[EMAIL PROTECTED]>
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, February 22, 2007 3:46:48 PM
Subject: Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In 
My Area









  







1) The number of repeaters in our area has 
increased slightly but the activity on any of them

is way-way down,  One local put a recorder on 
the output of one popular repeater channel

and found over a 24 hour period, it was in use less 
than 1% of the time.  Even the newer

IRLP and EchoLink repeaters attract very little 
interest.

 

2) Suspect the primary cause of the decline is due 
to alternative means of communication

being available.  Without a doubt, cell phones 
provide private communications world-wide

just about everywhere and whenever and, at 
relatively inexpensive prices.  Multi-channels

of TV with multi-content delivered via cable and 
satellite attract attention during the evening hours.

Ditto with satellite delivered multi-content radio 
channels available when mobile.  Then too of course,

are the ham forums on the internet such as this 
one, that competes for our time on the radio.

 

3) IMO this trend will not reverse but gradually 
continue.  A possible parallel would be packet radio.

In the beginning just as it was with repeaters, 
there was a rush to install packet network nodes

over most of the US.  Clubs and individuals 
were proud to be involved with the 'digital revolution.

User interest waned and as time passed the network 
deteriated.  Today there are very few

"live" users.

 

73 de Jack -  N7OO

 


  - Original Message - 

  From: 
  Tony 
  L. 

  To: Repeater-Builder@ yahoogroups. com 
  

  Sent: Thursday, February 22, 2007 12:36 
  PM

  Subject: [Repeater-Builder] OT- Activity 
  Level On Ham Repeaters Way Down In My Area

  


  
  The number of active ham repeaters in my area is way, way down in 
  
comparison to levels of 10 years ago. It isn't uncommon to monitor a 
  
repeater frequency and hear no traffic for weeks. Some clubs & 
  
individuals have just walked away from coordinated pairs.

However, 
  there are a few repeaters that have remained active, although 
certainly 
  not to the extent they were in the past. Interestingly, even 
though 
  traffic is way down, there's still a waiting list in my area for 
  
coordinated pairs on all bands.

Questions:

1) Has there been 
  a decline in traffic and the number of active 
repeaters in your 
  area?

2) If so, what do you feel the primary cause is?

3) What 
  can be done to generate renewed interest? 




  



  

[Repeater-Builder] Tone squelch vs. carrier squelch

[Brian Rau]

Ok, I know all the usual reasons for using input tones on a repeater,
but I have more of a theoretical performance question.  Again, I'm
putting together a portable VHF repeater out of a pair of Icom mobiles
(IC-F121) for search-and-rescue use.  Since it's for temporary,
emergency use, my primary concern is weak-signal performance,
particularly being able to hear someone out in the field with a 5W
handheld and a rubber duck.  Here's my question: For the best chance
of allowing my repeater to hear that weak signal, am I better off
using an input tone and turning the receiver squelch way down (perhaps
even all the way), or using no input tone and plain old carrier
squelch (at a higher level)?  I'll almost certainly end up using a
receive tone on this thing anyway just to minimize interference
potential, but it seems to me that doing so might help improve my
"ears" as well.  Comments?

Brian
K9JVA

[Repeater-Builder] Re: Icom portable repeater help

[Brian Rau]

Just to follow up and "close the loop" on this thread, I got a
Sinclair MR256 mobile duplexer, threw together a quick test setup and
tested it on my drive to work this morning... it's kicking butt
compared to what it used to do using two separate antennas.  I'm now
getting good audio from five miles away using a 5W handheld, and no
real effort to optimize repeater site location (i.e. it's in my
backyard).  Thanks for the input, folks...

Brian
K9JVA

--- In Repeater-Builder@yahoogroups.com, "covertp9" <[EMAIL PROTECTED]>
wrote:
>
> I would think you'd be best served by getting the duplexer ASAP.  If
> your intent is to have a smaller, portable, quick to set up
> repeater... the duplexer allows you to eliminate one antenna &
> feedline, sets up more quickly, and works immediately without antenna
> jockeying, tuning, etc. (assuming your duplexer is properly tuned).  I
> have the IC221s combo up as a UHF repeater using a mobile duplexer. 
> Until I got the duplexer correctly tuned, the desense made the setup
> unusable.  However, now that it's tuned I get a 15-18 mile radius
> coverage from the colinear ground plane 18 feet above the back of my
> garage rrof.  It works as expected.
> - WB2ULR
> 
> --- In Repeater-Builder@yahoogroups.com, "Brian Rau"  wrote:
> >
> > I'm putting together a portable "suitcase" repeater for our search and
> > rescue team, using Icom F121 radios per this article:
> > 
> >
>
http://www.repeater-builder.com/icom/repeater-mod-for-icom-ic121-221-series.rtf
> > 
> > I've got the two radios together and working, my question is: has
> > anyone had success with this configuration using two separate antennas
> > (no duplexer)?  I've tried using two twinlead J-poles, one at the top
> > of a 25' mast and one at ground level (tried both RX and TX at the
> > top, TX at top seems to work better), I've also tried a home-built 1/4
> > wave with four radials at the top (TX) with a 1/4 wave magmount on a
> > car directly below.  I can hit the repeater with a 5W handheld from a
> > good long distance away, and get the squelch tail for the programmed
> > hang time.  However, I don't get any audio repeated much farther than
> > a half mile to a mile away.  I can do handheld-to-handheld simplex a
> > good deal farther than this.
> > 
> > I have permission to use a 5.5 MHz split pair of frequencies in the 
> > 150 MHz range, which is what I've done all testing on.  It sure acts
> > like the TX is desensing the receiver.  We ultimately may want to
> > incorporate a mobile duplexer (Sinclair or similar) into the box
> > anyway just to be able to use a single antenna, but I'm surprised this
> > isn't working better with two antennas mounted directly above/below
> > each other.  Interestingly, Icom apparently offers this configuration
> > (two F121 mobiles in a Pelican case) as a standard "portable repeater"
> > product now, and the duplexer is an option, so I'm wondering under
> > what circumstances this thing will work without a duplexer?
> > 
> > Any comments or suggestions are appreciated.
> > 
> > Brian
> > K9JVA
> >
>

Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In My Area

[Jim B.]

[EMAIL PROTECTED] wrote:
> I see the same thing even in the big cities - Los Angeles, San
> Francisco, Chicago, Seattle, Vancouver B.C., etc. As you tune across
> 2-Meters, 220 and 440 MHz, most Repeaters are quiet, most of the
> time. You can often scan the entire band(s) from a clear location and
> never hear one signal.

For the most part though, even at it's peak, repeaters were not very 
busy during the day, unless there was a couple of old f***s sitting at 
home tying it up all day, which is something we had to put a stop to. 
Guys that could easily talk simplex parking on a repeater all day 
instead is just not good practice. Not to mention that they were being 
heard on 3-4 different repeaters in the summer.
Most people are at work during the day, so the busiest time is mornings 
and evenings-"drive time".
-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Tone squelch vs. carrier squelch

[no6b]

At 2/23/2007 07:05, you wrote:
>Ok, I know all the usual reasons for using input tones on a repeater,
>but I have more of a theoretical performance question.  Again, I'm
>putting together a portable VHF repeater out of a pair of Icom mobiles
>(IC-F121) for search-and-rescue use.  Since it's for temporary,
>emergency use, my primary concern is weak-signal performance,
>particularly being able to hear someone out in the field with a 5W
>handheld and a rubber duck.  Here's my question: For the best chance
>of allowing my repeater to hear that weak signal, am I better off
>using an input tone and turning the receiver squelch way down (perhaps
>even all the way), or using no input tone and plain old carrier
>squelch (at a higher level)?  I'll almost certainly end up using a
>receive tone on this thing anyway just to minimize interference
>potential, but it seems to me that doing so might help improve my
>"ears" as well.  Comments?
>
>Brian
>K9JVA

Generally speaking, CTCSS squelch is slightly more sensitive than 
noise-activated carrier squelch.  However, either one, when properly 
adjusted, should afford sufficient sensitivity so as to not reject 
intelligible signals.

A very common practice is to logically "AND" the CTCSS & carrier squelch 
outputs to provide squelch tail reduction (or in the case of Micor squelch, 
squelch tail elimination on strong signals) while only allowing signals 
intended for repeating to activate the system.  That way you get the best 
of both squelches.  Alternatively, you can use only CTCSS squelch with an 
audio delay module (ADM) to eliminate the squelch tail, but the CTCSS board 
will need to have a rather fast decay & the ADM has to be set to a long 
delay value.

Bob NO6B

Re: [Repeater-Builder] Tone squelch vs. carrier squelch

[w5zit]

A lot depends on the performance of the tone decoder you use. I have a 
couple of repeaters using Zetron 38A controllers that detect the tone 
way down in the noise, and one of them is operating with the squelch 
open so it is only controlled by the tone. It will stay keyed reliably 
with no discernible voice coming through, just sounds like open squelch 
noise. But in fact there is a weak signal there transmitting the 
correct tone. The only problem that I have with that is the long open 
squelch burst at the end of each transmission.

So, depending on your tone detector performance, you will probably get 
reliable operation down into the noise with the tone detector only 
controlling your repeater.

73 - Jim W5ZIT

-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Fri, 23 Feb 2007 8:05 AM
Subject: [Repeater-Builder] Tone squelch vs. carrier squelch

Ok, I know all the usual reasons for using input tones on a repeater,
but I have more of a theoretical performance question. Again, I'm
putting together a portable VHF repeater out of a pair of Icom mobiles
(IC-F121) for search-and-rescue use. Since it's for temporary,
emergency use, my primary concern is weak-signal performance,
particularly being able to hear someone out in the field with a 5W
handheld and a rubber duck. Here's my question: For the best chance
of allowing my repeater to hear that weak signal, am I better off
using an input tone and turning the receiver squelch way down (perhaps
even all the way), or using no input tone and plain old carrier
squelch (at a higher level)? I'll almost certainly end up using a
receive tone on this thing anyway just to minimize interference
potential, but it seems to me that doing so might help improve my
"ears" as well. Comments?

Brian
K9JVA

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Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In My Area

[Jim B.]

In a message dated 2/22/2007 11:40:17 A.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
> 
> The number of active ham repeaters in my area is way, way down in  
> comparison to levels of 10 years ago. It isn't uncommon to monitor a  
> repeater frequency and hear no traffic for weeks. Some clubs &  
> individuals have just walked away from coordinated pairs.
> 
> However,  there are a few repeaters that have remained active, although 
> certainly  not to the extent they were in the past. Interestingly, even 
> though  traffic is way down, there's still a waiting list in my area for  
> coordinated pairs on all bands.
> 
> Questions:
> 
> 1) Has there been  a decline in traffic and the number of active 
> repeaters in your  area?

No. If anything, there are more repeaters. But the activity is about the 
same, so there are now 'busy' repeaters and 'quiet' repeaters. (And then 
there's the paper repeaters...)

> 2) If so, what do you feel the primary cause is?

It is true that people communicate more on the internet then just 
picking up a mic...sorta like right here on the list...;c}

> 3) What  can be done to generate renewed interest? 

I don't see a lack of interest in amateur radio as such, but there is a 
lack of interest in public service events and emergency communications. 
The number of hams involved in that area has dropped off. Do I have an 
answer? No-if I did, I'd do something about it...

[EMAIL PROTECTED] wrote:
> The reason for the waiting list for coordinating pairs even in  the presence 
> of declining repeater usage is because there is generally no  requirement for 
> a repeater to maintain a threshold activity level after  coordination. 
> Implementing such a requirement to retain coordination  would undoubtedly 
> free up 
> pairs, but man, it would get  ugly. 

And would be an incredibly stupid idea. The vast majority of the 
repeaters whose owners are pro-actively letting their repeaters be used 
for emergency communications are the least used. And that's a good 
thing, because then it's available when it's needed. While I firmly 
believe that a radio system needs to be used on a regular basis so 
people are familiar with it, by the same token, if it's tied up all day 
long with superfluous chit-chat between a couple of truck drivers that 
don't even live in the area, and wouldn't know how to help in an 
emergency anyway, the repeater is of little use either.

> ** AOL now offers free 
> email to everyone.  Find out more about what's free from AOL at 
> http://www.aol.com.
> 

What the heck is this? Please post in plain text, not HTML!

-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Jim B.]

Ken Harrison wrote:
> Thanks for the recommendation, Don.  Though I'm sure a MastrII would
> be a great conversion for 220, we (in the group sense) want to try to
> save some of our money to get a remote base setup going on our
> repeater, too.   Our small savings would be wiped out to replace the
> entire repeater, in spite of it being handy to have a complete spare
> should there be a problem in the future.
> 
> Thanks,
> Ken

Um-converting a MastrII or other commercial station is MUUCH 
cheaper then buying one of those made-for-ham pieces of junk.
You'll spend $1000-1500 for a Maggiore/Kendecom/Spectrum, where you can 
convert an MII for a couple of hundred.

-- 
Jim Barbour
WD8CHL

[Repeater-Builder] Re: 220 repeater receiver recommendations?

[skipp025]

> "Ken Harrison" <[EMAIL PROTECTED]> wrote:
> Yes, I figured I might get a few different opinions.  I
> certainly don't want to start a war, though!  :-)

Which is one of the reasons I tried to toss a "one of everything" 
type reply.  The more information you have... the more choices you 
get to make. 

> Regarding 3rd v. 5th overtone, no real reasoning there.  Spectrum's
> current receiver is a 5th overtone.  Our old one is a 3rd.  (New
> crystal needed...)

Depending on the receiver design... and your location..  you might 
have a problem receiving an image signal from the adjacent tv channel. 
The biggest sinner is probably the original Icom 3at portable radio. 

You can hear your repeater and the afternoon Soap Opera's at the same 
time.  So the 5th overtone change/revision might be a method to avoid 
an IF Image or injection problem... but I don't yet know for sure. 

> You're a little tuff to pin down on an opinion, though.  I see you
> like Hamtronics well enough to try one of their synthesized models,
> you have a Hi Pro that keeps on playing like the energizer bunny, 
> and you like Spectrum's audio interface.  

I also have a Spectrum Repeater in operation. Its had it's war stories 
but once I got them sorted out it's been playing well for a long 
time. Most of the grief has been the transmitter and their use of the 
wrong type (not rated for rf) capacitors in the rf chain. I changed 
them out and it's been rock and roll ever since. 

> Haa.  Are you a politician by chance?  (snicker)

Moderate republican on most issues... 

> I'm not totally satisfied with customer service from Spectrum.  
> The attitude presented was problematic, to be sure.

Spectrum has done all they could to shoot their business in the foot. 
You'd think people would learn from their experiences or just go out 
of business.  Somehow Spectrum keeps on ticking... 

I like to buy their tx/rx boxes at flea markets. Their basic design 
is pretty good and I have the docs on most of their stuff. So they 
can be a great deal in the right time and place.  But there is so 
much used/surplus gear flooding the market right now that almost 
anything you buy should be a good deal. 
 
> Anyway, we'll look at all the companies presented with an open mind
> and try to forget the bad incident we had with one of them.
> Thanks-
> Ken

Group member and long time friend Eric bought the GE 220 conversion 
from the Repeater Builder (Scott/Kevin) Bunch at Dayton last year. 
He's been very happy with the results... so if you  have a GE radio 
around that fits the conversion... it's a great way to go.  

We're still trying to get the braut smell out of the Dayton purchased
surplus repeater gear. 

cheers, 
skipp 

[Repeater-Builder] Antenex YDA4404 antenna

[john_moody88]

Has anyone had any experience with the Antenex YDA4404 antenna??
It is cut for 440-460Mhz which I like better than the DB408-B
which is cut for 450-470Mhz.
Thanks,
John W5RVT

[Repeater-Builder] Affordable P25 Repeaters?

[Tony L.]

What manufacturers currently have P25 capable repeaters on the market?

[Repeater-Builder] Re: Antenex YDA4404 antenna

[skipp025]

If the driven element is the loop dipole type like the Antennex 
yagi I have here in front of me... it works killer (great)!  

You can order the Antennex Yagi with a 430-450 range. I can supply 
with the part number if you need it. The loop dipole driven element 
is in my opinion one of the best possible methods to feed the antenna 
when you need the true stated bandwidth. 

cheers,
skipp 

> "john_moody88" <[EMAIL PROTECTED]> wrote:
>
> Has anyone had any experience with the Antenex YDA4404 antenna??
> It is cut for 440-460Mhz which I like better than the DB408-B
> which is cut for 450-470Mhz.
> Thanks,
> John W5RVT
>

[Repeater-Builder] GE MASTR II Parts

[Jim, K8COP]

I have some VHF and possibly of some UHF (406-420 Rxs)  Cleaning the 
garage.  Prices are very reasonable.  
I am located in the Muskegon, MI. area for anyone in Michigan that 
wants to pick up.

E-mail me direct at [EMAIL PROTECTED]


Thanks,

Jim, K8COP

RE: [Repeater-Builder] Affordable P25 Repeaters?

[Juan Tellez]

Try this:  http://www.danelec.com/

 

Juan

 

Asunto: [Repeater-Builder] Affordable P25 Repeaters?

 

What manufacturers currently have P25 capable repeaters on the market?

 

Re: [Repeater-Builder] Affordable P25 Repeaters?

[Jim B.]

Tony L. wrote:
> What manufacturers currently have P25 capable repeaters on the market?

Motorola, M/A-Com, EADS, Daniels, EFJ, Tait, maybe Racal. Several others 
are reselling Daniels, maybe other brands.
Also, Raytheon has a P25CC controller that is supposed to add P25 to an 
existing base, like adding a tone panel or LTR panel. I'm looking into 
to it to find out more now.

-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Affordable P25 Repeaters?

[Phil]

might take a look at a Quantar if you already have one, or even a Mastr III can 
be upgraded (if not already)
   
  We've successfully deployed Daniels and Quantar repeater setups w/ P25.

 
-
Want to start your own business? Learn how on Yahoo! Small Business.

Re: [Repeater-Builder] Antenex YDA4404 antenna

[n6lrv]

Yes, the YDA4404 is indeed cut for the advertised 440-460Mhz subband. I have 
one working just fine for a couple of years now.
Gary
 john_moody88 <[EMAIL PROTECTED]> wrote: 
> Has anyone had any experience with the Antenex YDA4404 antenna??
> It is cut for 440-460Mhz which I like better than the DB408-B
> which is cut for 450-470Mhz.
> Thanks,
> John W5RVT
> 
> 
> 
> 
> 
>  
> Yahoo! Groups - Join or create groups, clubs, forums & communities. Links
> 
> 
> 

Re: [Repeater-Builder] Re: Antenex YDA4404 antenna

[n6lrv]

Careful! Antenex and Antennex are two different companies. The antenna John is 
asking about is a 4 bay dipole array (non-folded).
Gary

 skipp025 <[EMAIL PROTECTED]> wrote: 
> 
> If the driven element is the loop dipole type like the Antennex 
> yagi I have here in front of me... it works killer (great)!  
> 
> You can order the Antennex Yagi with a 430-450 range. I can supply 
> with the part number if you need it. The loop dipole driven element 
> is in my opinion one of the best possible methods to feed the antenna 
> when you need the true stated bandwidth. 
> 
> cheers,
> skipp 
> 
> > "john_moody88" <[EMAIL PROTECTED]> wrote:
> >
> > Has anyone had any experience with the Antenex YDA4404 antenna??
> > It is cut for 440-460Mhz which I like better than the DB408-B
> > which is cut for 450-470Mhz.
> > Thanks,
> > John W5RVT
> >
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups - Join or create groups, clubs, forums & communities. Links
> 
> 
> 

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[cruising7388]

 
For Scott:
 
With respect to using the GE MII mobile frame for repeater  applications:
 
1. Can  you say categorically that there is sufficient TX/RX shielding  to 
prevent any desense  at any power level the conversion is capable of  operating?
 
2. When these converted mobiles operate with reduced TX power, what happens  
to the output impedance of the TX? Is it still 50 ohms? If not, does this 
affect  the physical length of the half wave interconnect cables often 
suggested 
between  the TX and an isolator and/or the cavities?
 
3. If the output of the TX is other than 50 ohms as a result of a power  
level change,  does it upset the adjustment of the downstream isolator that  
has 
been tuned by a tracking generator?
 
Tks
 
Bruce
K7IJ
 
 
 
 
In a message dated 2/22/2007 7:02:38 P.M. Pacific Standard Time,  
[EMAIL PROTECTED] writes:

Ken,
 
We not only do complete repeaters, we can custom  build just about anything 
you want or need. We can simply build a rock-solid  high-quality 220 receiver 
for you. We have done several receivers in the past  that are rack mountable in 
a 2 unit rack space. I have a GE mastr II receiver  that I am just finishing 
up. It came out looking so nice that I am going to  take pictures as a show 
piece. Micor receivers would be VERY similar in  construction.
 
In my opinion, 2 things:
 
1. A Micor makes a much better repeater on 2M and  220 than a GE MII. (sorry 
GE loyalists!!) I think a Mastr II makes a much  better repeater on UHF (sorry 
Micor loyalists!!) I would suggest a Micor for  your 220 Machine.
 
2. If you're going to spend money on a new  receiver, why not spend a bit 
more and get a completely new machine. Think  about it, if your receiver is not 
100%, what's saying that your transmitter is  running at 100%? The notable 
thing about spectrum repeaters is that they lived  up to their name, they took 
up 
the WHOLE spectrum. This might even be what is  happing that you assume is a 
bad receiver. Instead of a bad receiver, you may  have a spurious transmitter 
that is totally wiping your receiver off the map.  Duplexers are meant to 
isolate, but there is only so much they can  isolate.
 
If you'd like a quote on a new machine or a quote  for a new receiver, feel 
free to e-mail or call.
 
Scott - Owner Repeater-Builder (the  company)
_www.repeater-www.repeaterwww.repeater_ 
(http://www.repeater-builder.com/custombuilt/) 
 
Scott Zimmerman 
Amateur Radio Call  N3XCC
474 Barnett Road
Boswell, PA 15531

- Original Message - 
From: _Ken  Harrison_ (mailto:[EMAIL PROTECTED])  
To: [EMAIL PROTECTED] 
(mailto:Repeater-Builder@yahoogroups.com)   
Sent: Thursday, February 22, 2007 8:39  PM
Subject: [Repeater-Builder] Re: 220  repeater receiver recommendations?



Thanks for the recommendation, Don. Though I'm sure a MastrII would
be  a great conversion for 220, we (in the group sense) want to try to
save  some of our money to get a remote base setup going on our
repeater, too.  Our small savings would be wiped out to replace the
entire repeater, in  spite of it being handy to have a complete spare
should there be a  problem in the future.

Thanks,
Ken

--- In [EMAIL PROTECTED] 
(mailto:Repeater-Builder@yahoogroups.com) ,  "Don KA9QJG" <[EMAIL PROTECTED]> 
wrote:
>
> Ken first of All I  noticed You stated Our group, so I would assume
You have
> others  kicking in to the Cost, I do not and I had Scott build Me up
a  220
> Repeater System, He did it in the process of Building a house  and
Moving All
> I had to do was Program the Controller, Hook up  the Amp, Power Supply
> Duplexers, and Ant, I have never had any  Problems for over a Yr.







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[Repeater-Builder] Re: Antenex YDA4404 antenna

[skipp025]

>> Careful! Antenex and Antennex are two different companies. 
>> The antenna John is asking about is a 4 bay dipole array 
>> (non-folded). Gary

Christmas..! must have been drunk in my beer again?  Well... I've 
got both types of those antennas here... actually one at the top 
of a repeater site tower. 

I've used (and am currently using the YDA4404 450-470 model for a ham 
repeater off a master antenna system.  It also works killer! One 
item to our advantage is how the beam-tilt seems to move down some 
amount as you go below the 450 band edge. Great for us from a 2,350 
foot mountain top.  Since California is "right side up" on our 440 
to 450 band everything works out because our repeater receivers 
normally use the 455-449.9875 segment.

Now... back to my face down on the table... 

cheers,
skipp 

ps: thank you Gary for the rehab email notice

 
> If the driven element is the loop dipole type like the Antennex 
> yagi I have here in front of me... it works killer (great)!  
> 
> You can order the Antennex Yagi with a 430-450 range. I can supply 
> with the part number if you need it. The loop dipole driven element 
> is in my opinion one of the best possible methods to feed the antenna 
> when you need the true stated bandwidth. 
> 
> cheers,
> skipp 
> 
> > "john_moody88"  wrote:
> >
> > Has anyone had any experience with the Antenex YDA4404 antenna??
> > It is cut for 440-460Mhz which I like better than the DB408-B
> > which is cut for 450-470Mhz.
> > Thanks,
> > John W5RVT
> >
>

Re: [Repeater-Builder] Affordable P25 Repeaters?

[Jim B.]

Phil wrote:
> might take a look at a Quantar if you already have one, or even a
> Mastr III can be upgraded (if not already)

Not all of either can be upgraded-only the newer ones. Older Quantars 
and MIII's don't have the hardware to accomodate it.

BTW-Kenwood, Icom, Vertex, and Relm are reselling Daniels. And I think a 
couple of others do too.

-- 
Jim Barbour
WD8CHL

[Repeater-Builder] Re: 220 repeater receiver recommendations?

[skipp025]

> With respect to using the GE MII mobile frame for repeater  
> applications:
>  
> 1. Can  you say categorically that there is sufficient TX/RX 
> shielding  to prevent any desense at any power level the 
> conversion is capable of  operating?

Depends on the pa power level. You can easily test for desense 
both external and "in cabinet". 

> 2. When these converted mobiles operate with reduced TX power, 
> what happens to the output impedance of the TX? Is it still 
> 50 ohms? 

Depends a lot on the pa circuit, it's laytout and how you reduce 
the power output. 

> If not, does this affect the physical length of the half wave 
> interconnect cables often suggested between  the TX and an 
> isolator and/or the cavities?

The practical answer... Again it depends on the above mentioned and 
how nit picky you are. Most people say the tx or pa to circulator 
cable length is not critical. I say it is for my own reasons and 
experience.  Keep in mind you can easily match non 50 ohm outputs 
to 50 ohms using special coax values/lengths or various combos 
there of. 
 
> 3. If the output of the TX is other than 50 ohms as a result of 
> a power level change,  does it upset the adjustment of the 
> downstream isolator that  has been tuned by a tracking generator?

The answer you're probably looking for is yes... but again each 
case is specific to the respective hardware, circuit and all the 
related factors. 

An adjustable Circulator/Isolator is best setup under actual rf 
power... tracking generator will not often give the best adjustment...
 sometimes only close. 

Lunch hour... food... time to go, back later. 

cheers, 
skipp 

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Jim B.]

[EMAIL PROTECTED] wrote:
>  
> For Scott:
>  
> With respect to using the GE MII mobile frame for repeater  applications:
>  
> 1. Can  you say categorically that there is sufficient TX/RX shielding  to 
> prevent any desense  at any power level the conversion is capable of  
> operating?

At UHF-categorically yes, because both the MII and the Micor were 
avialable from the factory in full duplex versions for certain applications.

> 2. When these converted mobiles operate with reduced TX power, what happens  
> to the output impedance of the TX? Is it still 50 ohms? If not, does this 
> affect  the physical length of the half wave interconnect cables often 
> suggested 
> between  the TX and an isolator and/or the cavities?

It probably isn't exactly 50 ohms, but should be close. And the cables 
from the duplexer to the radio do NOT *REPEAT* NOT need to be an exact 
length. This again indicates an impedance mismatch in the duplexer and 
it should be retuned. (or a bad antenna/load)

> 3. If the output of the TX is other than 50 ohms as a result of a power  
> level change,  does it upset the adjustment of the downstream isolator that  
> has 
> been tuned by a tracking generator?

No it should not. The load on the 3rd port of the isolator is still 50 
ohms, so it should not be an issue. And I don't see the impedance of a 
good PA like an MII or Micor changing off of 50 ohms enough to matter.
Other brands, who knows.

-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Affordable P25 Repeaters?

[mch]

Motorola, M/A-Com, EFJ, Kenwood, Icom, Relm/BK, Daniels. (likely others) 
(if you mean P25 spec'ed)

Joe M.

Tony L. wrote:
> 
> What manufacturers currently have P25 capable repeaters on the market?

Re: [Repeater-Builder] Re: Antenex YDA4404 antenna

[n6lrv]

The 450-470Mhz version is the YDA4504 but this experience of yours is helpful. 
I had a new YDA4504 but traded it back to Antenex for a YDA4404 thinking the 
4504 wouldn't tune down far enough to work on our receive (441 range).  
Experience with other Antenex antennas prompted me to pursue the swap. I didn't 
even try the 4504, guess I should have to see just how low it would go.
Gary
 skipp025 <[EMAIL PROTECTED]> wrote: 
> I've used (and am currently using the YDA4404 450-470 model for a ham 
> repeater off a master antenna system.  It also works killer! One 
> item to our advantage is how the beam-tilt seems to move down some 
> amount as you go below the 450 band edge. Great for us from a 2,350 
> foot mountain top.  Since California is "right side up" on our 440 
> to 450 band everything works out because our repeater receivers 
> normally use the 455-449.9875 segment.
> 
> Now... back to my face down on the table... 
> 
> cheers,
> skipp 

Re: [Repeater-Builder] 220 repeater receiver recommendations?

[Nate Duehr]

On 2/22/07, Ken Harrison <[EMAIL PROTECTED]> wrote:
> Our group is in need of replacing the receiver on our 220 box and I
> wanted to solicit some opinions from the group.

> What are you using and are you happy with it?  Would you buy any
> particular one again?  Why or why not.

Currently running a Kendecomm.  Hate it.

Pots are squirrelly (low quality) for any possible adjustment, the
thing is impossible to work on in the rack - have to pull it out,
remove a billion screws, and put it back in -- it won't stay on
frequency... and it's installed in a temperature-controlled climate,
and the meters on the front have had something weirdly wrong with them
for years... trying to decipher them into useful information -- ain't
happenin'.

I will be happy to pitch it off the side of something very very tall
as soon as...

We're replacing it with a Mastr II conversion -- that supposedly I'm
doing -- well, I got the first one done and it's receiver is very
deaf... (starts to hear signal at 2uV -- no, not .2uV... 2!!
g)...

So I'm struggling through trying to figure out what went wrong...

It has been taking up all of my spare time for about 5 days straight
now, and my wife is learning to enjoy the sound of 1000 Hz test tone
floating up from the basement...

At least she knows where I am!  (GRIN)

If you're a masochist... or if you're a "hard learner" like myself but
want to learn... try the mods yourself.

If you enjoy your nice normal sane life, buy from Kevin and Scott.
:-) :-) :-)  For the amount of work involved and loss of hair and
sanity, it's well worth the price they're asking.

Oh almost forgot... Pitch the Spectrum off the side of something tall
too, when you get the chance.

(You said you wanted real opinions!!!  GRIN...)

I should have shot time-lapse video of me doing this Mastr II
conversion... it could have become a popular comedy short on YouTube
titled, "Never Let the Data Geek Have a Screwdriver".

But there is something insanely satisfying about taking a propane
torch to a radio for the first time ever in your life... you can add
in the evil mad scientist laugh for added effect, too... but at 1AM in
the driveway, no one heard it.

Nate WY0X

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Scott Zimmerman]

With respect to using the GE MII mobile frame for repeater applications:

> 1. Can  you say categorically that there is sufficient TX/RX shielding to 
> prevent any desense  at any power level the conversion is capable of 
> operating?

In my experience, yes. In fact, we have had several repeaters that the 
sensitivity actually gets BETTER with the transmitter active. (due to the 
correct 50 impedance being applied to the TX port of the duplexer) The only 
problems we have had with in-cabinet de-sense go back to issues with a 
transmitter multiple getting into a sensitive spot of the receiver. This is a 
well known phenomenon on UHF Mastr II's, but it also happens on converted 220 
micors and MII's. I have been wanting to write up this research for some time. 
I will try to do it as soon as I can.

2. When these converted mobiles operate with reduced TX power, what happens to 
the output impedance of the TX? Is it still 50 ohms? If not, does this affect 
the physical length of the half wave interconnect cables often suggested 
between the TX and an isolator and/or the cavities?

As others have stated, it may not be *exactly* 50j0, but it's close enough. 
Realize that most of the "50 ohm" coax cable actually spec'd to be 52 ohm 
nominal!! I would think that the cable being 2 ohms off would be more detriment 
than the 50ohm designed output / input impedance that might move fractions of 
an ohm in impedance due to being tuned a few MHz from it's design frequency. If 
you want to get that picky, should a PA's output be tuned for 50 ohms when the 
frequency is changed from let's say 155.xx to 158.xxx? I would think that if 
the designers would have thought the port impedance to be that critical, they 
would have made provisions to adjust it.

As far as our 220 modifications go; we use a M57774 power module. We DO NOT 
modify/retune the VHF pa to 220. If we did, we might run into design issues 
where impedance problems might rare their ugly head. We just use an 
off-the-shelf solution that works well.

If not, does this affect the physical length of the half wave interconnect 
cables often suggested between the TX and an isolator and/or the cavities?

3. If the output of the TX is other than 50 ohms as a result of a power level 
change,  does it upset the adjustment of the downstream isolator that has been 
tuned by a tracking generator?

Can't say. I have no experience. I will defer this question to others.

Scott

Scott Zimmerman
Amateur Radio Call N3XCC
612 Barnett Rd
Boswell, PA 15531

  - Original Message - 
  From: [EMAIL PROTECTED] 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, February 23, 2007 2:24 PM
  Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?



  For Scott:

  With respect to using the GE MII mobile frame for repeater applications:

  1. Can  you say categorically that there is sufficient TX/RX shielding to 
prevent any desense  at any power level the conversion is capable of operating?

  2. When these converted mobiles operate with reduced TX power, what happens 
to the output impedance of the TX? Is it still 50 ohms? If not, does this 
affect the physical length of the half wave interconnect cables often suggested 
between the TX and an isolator and/or the cavities?

  3. If the output of the TX is other than 50 ohms as a result of a power level 
change,  does it upset the adjustment of the downstream isolator that has been 
tuned by a tracking generator?

  Tks

  Bruce
  K7IJ




  In a message dated 2/22/2007 7:02:38 P.M. Pacific Standard Time, [EMAIL 
PROTECTED] writes:
Ken,

We not only do complete repeaters, we can custom build just about anything 
you want or need. We can simply build a rock-solid high-quality 220 receiver 
for you. We have done several receivers in the past that are rack mountable in 
a 2 unit rack space. I have a GE mastr II receiver that I am just finishing up. 
It came out looking so nice that I am going to take pictures as a show piece. 
Micor receivers would be VERY similar in construction.

In my opinion, 2 things:

1. A Micor makes a much better repeater on 2M and 220 than a GE MII. (sorry 
GE loyalists!!) I think a Mastr II makes a much better repeater on UHF (sorry 
Micor loyalists!!) I would suggest a Micor for your 220 Machine.

2. If you're going to spend money on a new receiver, why not spend a bit 
more and get a completely new machine. Think about it, if your receiver is not 
100%, what's saying that your transmitter is running at 100%? The notable thing 
about spectrum repeaters is that they lived up to their name, they took up the 
WHOLE spectrum. This might even be what is happing that you assume is a bad 
receiver. Instead of a bad receiver, you may have a spurious transmitter that 
is totally wiping your receiver off the map. Duplexers are meant to isolate, 
but there is only so much they can isolate.

If you'd like a quote on a new machine or a quote for a new receiver, feel 
fr

Re: [Repeater-Builder] Circulators FS

[n9mep]

All the equipment has been sold   Thanks to all that were  
interested...
 
Gerry
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Re: [Repeater-Builder] Circulators FS

[n9mep]

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Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[cruising7388]

 
In a message dated 2/23/2007 12:00:13 P.M. Pacific Standard Time,  
[EMAIL PROTECTED] writes:

It  probably isn't exactly 50 ohms, but should be close. And the cables 
from  the duplexer to the radio do NOT *REPEAT* NOT need to be an exact 
length.  This again indicates an impedance mismatch in the duplexer and 
it should  be retuned. (or a bad antenna/load)



I never suggested that the cable between the TX and the duplexer had to be  
an exact length and if the TX output is a true 50 ohms then any cable length  
produces no consequence at the cavity input. But if the TX impedance is not 50  
ohms,  I think any cable length other than half wave will make the cable a  
line transformer affecting  the impedance presented to the cavity with a  
quarter wave producing the greatest impedance shift. That's not necessarily a  
bad 
thing because the impedance match of a random length cable is statistically  
as likely to improve the TX/cavity match as it is to degrade it. Diddling 
around  with this proved to be so frustrating that I eventually caved in and 
installed a  Z-matcher at the TX output and tuned it for maximum cavity output 
at 
the  pass frequency. It seemed (and seems) to me that this is a cleaner way to 
deal  with the matching issue than trying to adjust BP/BR cavities with an 
input other  than 50 ohms.
 
You mentioned that the power adjustment levels would not affect TX output  
significantly on an M II or Micor. I'm not familiar with the power control  
network they employ but does the collector voltage on the output devices remain 
 
constant during power changes?  If not, how do you avoid significant output  
impedance shifts?
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[Repeater-Builder] Falcon 220 Mhz PA

[cruising7388]

Has anyone aboard had any experience with a 100 watt 220 Mhz PA made by  
Falcon Communications.
The model is #8252.  They quit production around 15 years  ago.
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Re: [Repeater-Builder] Tone squelch vs. carrier squelch

[Nate Duehr]

On 2/23/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:

> Generally speaking, CTCSS squelch is slightly more sensitive than
> noise-activated carrier squelch.  However, either one, when properly

There is one other minor factor in this... user radios... some aren't
set to output a reasonable CTCSS level.

We've had one or two users (since switching our systems to tone-only a
few years ago) who had to go deal with their rigs -- but it really
wasn't a repeater problem...

Nate WY0X

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Scott Zimmerman]

... but does the collector voltage on the output devices remain constant during 
power changes?  If not, how do you avoid significant output impedance shifts?

Yes. The final stages are kept at B+, the power set is done in the first stage 
in the PA; commonly known as the pre-driver or possibly pre-pre-driver stage.

Using your logic, one could ask if a change in B+ voltage would skew the output 
impedance?? Say the difference between 11v and 15v (not ALL power supplies are 
created equal.)

Scott

Scott Zimmerman
Amateur Radio Call N3XCC
612 Barnett Rd
Boswell, PA 15531

  - Original Message - 
  From: [EMAIL PROTECTED] 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Friday, February 23, 2007 4:06 PM
  Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?



  In a message dated 2/23/2007 12:00:13 P.M. Pacific Standard Time, [EMAIL 
PROTECTED] writes:
It probably isn't exactly 50 ohms, but should be close. And the cables 
from the duplexer to the radio do NOT *REPEAT* NOT need to be an exact 
length. This again indicates an impedance mismatch in the duplexer and 
it should be retuned. (or a bad antenna/load)

  I never suggested that the cable between the TX and the duplexer had to be an 
exact length and if the TX output is a true 50 ohms then any cable length 
produces no consequence at the cavity input. But if the TX impedance is not 50 
ohms,  I think any cable length other than half wave will make the cable a line 
transformer affecting  the impedance presented to the cavity with a quarter 
wave producing the greatest impedance shift. That's not necessarily a bad thing 
because the impedance match of a random length cable is statistically as likely 
to improve the TX/cavity match as it is to degrade it. Diddling around with 
this proved to be so frustrating that I eventually caved in and installed a 
Z-matcher at the TX output and tuned it for maximum cavity output at the pass 
frequency. It seemed (and seems) to me that this is a cleaner way to deal with 
the matching issue than trying to adjust BP/BR cavities with an input other 
than 50 ohms.

  You mentioned that the power adjustment levels would not affect TX output 
significantly on an M II or Micor. I'm not familiar with the power control 
network they employ but does the collector voltage on the output devices remain 
constant during power changes?  If not, how do you avoid significant output 
impedance shifts?




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1:26 PM

Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In My Area

[Nate Duehr]

On 2/23/07, Mike Morris WA6ILQ <[EMAIL PROTECTED]> wrote:



Well all the good (and not so good) sites are now owned by nationwide
conglomerates that are run by accountants, with site managers that
are more bill collector than radio tech (ever try to explain to an
accountant
why a 931mhz paging transmitter needs a circulator and a pass cavity?).
Nobody has the desire or the ability do a freebie.



There's something interesting to be seen in your reply here Mike, if we look
deeper.  Shorty's system is basically a "conglomerate" itself.  Perhaps the
only way to "beat" the giants is to join them?

Our club is pretty big too... four sites, more than that number of
repeaters.

Perhaps what we're REALLY lamenting here is that it's difficult (in every
field) for individuals to do business with corporate giants.  That's true
everywhere, in everything.

But a large club has resources to deal with the large site owners.

The downside to running a large club is that it's a full-time job just
keeping up with the paperwork.  You need a small army of people to handle
various things -- no individual can do a large club alone.

The individual that owns a site and sees a chance to let someone with

a knack for electronics learn something while having fun with 25 year
old radios that were slated for the junk pile is long gone.



Yeah but you can still learn those things with a "backyard" repeater on a
small tower.  People that really want to learn put things up... I've seen
hams call up their buddies (through our repeater... ha...) and discuss when
they'll be over to put up the repeater antenna on the other guy's tower,
where they're going to run the hardline, etc.  (I just laughed and chuckled
to myself -- they were using our repeater to coordinate the build-out of
another one... heh.  Should I have been offended?  Nahh. GRIN...)

And if you join one of the "conglomerate clubs" (new name?) and show even a
modicum of technical prowess, the existing techs will happily teach...

If you show up and claim you know everything there is to know already, that
doesn't work... it's all about attitude.

One of the reasons, of course, is that the stakes are higher.  I bet Shorty
can't (not won't... CAN'T) let just anyone wrench on his club's repeaters...
he would run the risk of cutting off a large portion of the network if he
let the wrong person without the right experience and attitude work on a
backbone link, for example.

But seriously -- he has "safety in numbers"... and I think he might have hit
on something -- how to handle the changes in site ownership and prices...
one way is to simply get bigger.

Our club would NEVER be able to charge what a West Coast system or East
Coast system can reasonably charge for membership... but our site costs are
(a little) lower, and we run donation drives for specific projects... if we
want something bad enough, people cough up a little extra cash and everyone
enjoys it... whatever it is... and we save up our sheckles to do big
projects that no one's interested in (like upgrade controllers -- only the
techies care)...

I'm not saying it's truth, just asking -- is one technique for dealing with
bigger site owners to get bigger ourselves?

Nate WY0X

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Bob Dengler]

At 2/23/2007 12:50 PM, you wrote:
>With respect to using the GE MII mobile frame for repeater applications:
>
> > 1. Can  you say categorically that there is sufficient TX/RX shielding 
> to prevent any desense  at any power level the conversion is capable of 
> operating?
>
>In my experience, yes. In fact, we have had several repeaters that the 
>sensitivity actually gets BETTER with the transmitter active. (due to the 
>correct 50 impedance being applied to the TX port of the duplexer)

Hmmm, that sounds rather unusual.  I can see the non-50 ohm impedance at 
the TX port pulling the notches on the RX side, but I wouldn't expect it 
to  affect the much broader RX pass response to the point of degraded RX 
sensitivity.

I have experienced this phenomenon before, but without a duplexer (or 
anything except a load for the TX) connected to the radio.  In my case it 
was due to "leaking" the RX RF from the signal generator (in this case just 
an HT) through the radio's case & the RF taking different "paths" through 
the radio to the RX between the TX on & TX off conditions.  Sometimes the 
RX would degrade with the TX on (as expected), & sometimes it would 
improve.  Both conditions were eliminated when the sig. gen. was properly 
coupled to the RX's RF input.

Bob NO6B

[Repeater-Builder] Re: Antenex YDA4404 antenna

[skipp025]

Well, with a lot of cake on my face I've just realized that Antennex 
and Antenex are two different companies. Funny because I get on the 
horn (phone) or online to order them and that small little fact has 
gone by me all these years. 

The yagi I mentioned in my first foot in mouth email is the YNT4307 
with a spec'd 430 to 450 MHz range. Just a killer antenna and probably 
one of the best dollar high performance yagi's we've used in some 
time. 

The YDA4504 is a very cost effective alternative to the higher priced 
Decibel, Sinclair Brands as seen in the Tesco Catalog. 

cheers,
skipp 

>- In Repeater-Builder@yahoogroups.com, <[EMAIL PROTECTED]> wrote:
>
> The 450-470Mhz version is the YDA4504 but this experience of yours
is helpful. I had a new YDA4504 but traded it back to Antenex for a
YDA4404 thinking the 4504 wouldn't tune down far enough to work on our
receive (441 range).  Experience with other Antenex antennas prompted
me to pursue the swap. I didn't even try the 4504, guess I should have
to see just how low it would go.
> Gary
>  skipp025 <[EMAIL PROTECTED]> wrote: 
> > I've used (and am currently using the YDA4404 450-470 model for a ham 
> > repeater off a master antenna system.  It also works killer! One 
> > item to our advantage is how the beam-tilt seems to move down some 
> > amount as you go below the 450 band edge. Great for us from a 2,350 
> > foot mountain top.  Since California is "right side up" on our 440 
> > to 450 band everything works out because our repeater receivers 
> > normally use the 455-449.9875 segment.
> > 
> > Now... back to my face down on the table... 
> > 
> > cheers,
> > skipp
>

[Repeater-Builder] Re: 220 repeater receiver recommendations? (MVP?)

[skipp025]

What about the GE MVP Scott..?  Would the conversion be available 
and similar for the MVP Mobile? 

skipp 

> "Scott Zimmerman" <[EMAIL PROTECTED]> wrote:
>
> With respect to using the GE MII mobile frame for repeater applications:
> 
> > 1. Can  you say categorically that there is sufficient TX/RX
shielding to prevent any desense  at any power level the conversion is
capable of operating?
> 
> In my experience, yes. In fact, we have had several repeaters that
the sensitivity actually gets BETTER with the transmitter active. (due
to the correct 50 impedance being applied to the TX port of the
duplexer) The only problems we have had with in-cabinet de-sense go
back to issues with a transmitter multiple getting into a sensitive
spot of the receiver. This is a well known phenomenon on UHF Mastr
II's, but it also happens on converted 220 micors and MII's. I have
been wanting to write up this research for some time. I will try to do
it as soon as I can.
> 
> 2. When these converted mobiles operate with reduced TX power, what
happens to the output impedance of the TX? Is it still 50 ohms? If
not, does this affect the physical length of the half wave
interconnect cables often suggested between the TX and an isolator
and/or the cavities?
> 
> As others have stated, it may not be *exactly* 50j0, but it's close
enough. Realize that most of the "50 ohm" coax cable actually spec'd
to be 52 ohm nominal!! I would think that the cable being 2 ohms off
would be more detriment than the 50ohm designed output / input
impedance that might move fractions of an ohm in impedance due to
being tuned a few MHz from it's design frequency. If you want to get
that picky, should a PA's output be tuned for 50 ohms when the
frequency is changed from let's say 155.xx to 158.xxx? I would think
that if the designers would have thought the port impedance to be that
critical, they would have made provisions to adjust it.
> 
> As far as our 220 modifications go; we use a M57774 power module. We
DO NOT modify/retune the VHF pa to 220. If we did, we might run into
design issues where impedance problems might rare their ugly head. We
just use an off-the-shelf solution that works well.
> 
> If not, does this affect the physical length of the half wave
interconnect cables often suggested between the TX and an isolator
and/or the cavities?
> 
> 3. If the output of the TX is other than 50 ohms as a result of a
power level change,  does it upset the adjustment of the downstream
isolator that has been tuned by a tracking generator?
> 
> Can't say. I have no experience. I will defer this question to others.
> 
> Scott
> 
> Scott Zimmerman
> Amateur Radio Call N3XCC
> 612 Barnett Rd
> Boswell, PA 15531
> 
>   - Original Message - 
>   From: [EMAIL PROTECTED] 
>   To: Repeater-Builder@yahoogroups.com 
>   Sent: Friday, February 23, 2007 2:24 PM
>   Subject: Re: [Repeater-Builder] Re: 220 repeater receiver
recommendations?
> 
> 
> 
>   For Scott:
> 
>   With respect to using the GE MII mobile frame for repeater
applications:
> 
>   1. Can  you say categorically that there is sufficient TX/RX
shielding to prevent any desense  at any power level the conversion is
capable of operating?
> 
>   2. When these converted mobiles operate with reduced TX power,
what happens to the output impedance of the TX? Is it still 50 ohms?
If not, does this affect the physical length of the half wave
interconnect cables often suggested between the TX and an isolator
and/or the cavities?
> 
>   3. If the output of the TX is other than 50 ohms as a result of a
power level change,  does it upset the adjustment of the downstream
isolator that has been tuned by a tracking generator?
> 
>   Tks
> 
>   Bruce
>   K7IJ
> 
> 
> 
> 
>   In a message dated 2/22/2007 7:02:38 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
> Ken,
> 
> We not only do complete repeaters, we can custom build just
about anything you want or need. We can simply build a rock-solid
high-quality 220 receiver for you. We have done several receivers in
the past that are rack mountable in a 2 unit rack space. I have a GE
mastr II receiver that I am just finishing up. It came out looking so
nice that I am going to take pictures as a show piece. Micor receivers
would be VERY similar in construction.
> 
> In my opinion, 2 things:
> 
> 1. A Micor makes a much better repeater on 2M and 220 than a GE
MII. (sorry GE loyalists!!) I think a Mastr II makes a much better
repeater on UHF (sorry Micor loyalists!!) I would suggest a Micor for
your 220 Machine.
> 
> 2. If you're going to spend money on a new receiver, why not
spend a bit more and get a completely new machine. Think about it, if
your receiver is not 100%, what's saying that your transmitter is
running at 100%? The notable thing about spectrum repeaters is that
they lived up to their name, they took up the WHOLE spectrum. This
might even be what is happing that you assume is a bad receiver.
Instead of a bad receiver, you may have a s

RE: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Gary Schafer]

A half wave length cable will act as an impedance transformer too. In this
case it will be a 1:1 transformation and if the output of the transmitter is
not 50 ohms then whatever impedance it is will be transformed to the cavity
input.

 

73

Gary  K4FMX

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Friday, February 23, 2007 4:06 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

 

In a message dated 2/23/2007 12:00:13 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:

It probably isn't exactly 50 ohms, but should be close. And the cables 
from the duplexer to the radio do NOT *REPEAT* NOT need to be an exact 
length. This again indicates an impedance mismatch in the duplexer and 
it should be retuned. (or a bad antenna/load)

I never suggested that the cable between the TX and the duplexer had to be
an exact length and if the TX output is a true 50 ohms then any cable length
produces no consequence at the cavity input. But if the TX impedance is not
50 ohms,  I think any cable length other than half wave will make the cable
a line transformer affecting  the impedance presented to the cavity with a
quarter wave producing the greatest impedance shift. 

 

 

 

Re: [Repeater-Builder] Re: Antenex YDA4404 antenna

[Mike Morris WA6ILQ]

At 11:41 AM 02/23/07, you wrote:
> >> Careful! Antenex and Antennex are two different companies.
> >> The antenna John is asking about is a 4 bay dipole array
> >> (non-folded). Gary
>
>Christmas..! must have been drunk in my beer again?  Well... I've
>got both types of those antennas here... actually one at the top
>of a repeater site tower.
>
>I've used (and am currently using the YDA4404 450-470 model for a ham
>repeater off a master antenna system.  It also works killer! One
>item to our advantage is how the beam-tilt seems to move down some
>amount as you go below the 450 band edge. Great for us from a 2,350
>foot mountain top.  Since California is "right side up" on our 440
>to 450 band everything works out because our repeater receivers
>normally use the 455-449.9875 segment.

Careful there - NorCal is repeater-input high, and repeater-output low,
SoCal is the reverse.  Dividing line is the Santa Maria River.  There
are valid arguments for each method... Makes it lots of fun for the
guys in the middle ... they have to pick the frequencies carefully to
avoid lockups and a system output capturing someone elses input.

>Now... back to my face down on the table...

(Sound of snoring)

>cheers,
>skipp

Mike WA6ILQ

[Repeater-Builder] 440-450 band plan (The normal North vs So Cal :-)

[skipp025]

Hi Mike, 

Even more fun is the frequent band openings.  One repeater in the 
SF Bay Area will lock up its reverse co-channel So Cal machine. Both 
have no practical time-out timers. Happens more than a few times 
a month... sometimes a few times in one week. 

I can't help it if you guys are "upside down"...  :-) 

cheers,
s. 


> Careful there - NorCal is repeater-input high, and repeater-output 
> low, SoCal is the reverse.  Dividing line is the Santa Maria River. 
> There are valid arguments for each method... Makes it lots of fun 
> for the guys in the middle ... they have to pick the frequencies 
> carefully to avoid lockups and a system output capturing someone 
> elses input.

Re: [Repeater-Builder] OT- Activity Level On Ham Repeaters Way Down In My Area

[Nate Bargmann]

* Tony L. <[EMAIL PROTECTED]> [2007 Feb 22 13:40 -0600]:

> 1) Has there been a decline in traffic and the number of active 
> repeaters in your area?

Not really.  Activity has always been spares, even when I was first
licensed as a Tech in 1985.  We have a low density of hams to begin
with since this is a rural area and even fewer of those are active.

> 2) If so, what do you feel the primary cause is?

I always blamed on the low number of hams and our work schedules. 
Personal lives don't mesh much at all usually.  Back when packet was
the going thing, it was very popular here because we could communicate
in without having to match schedules.  Email has replaced packet over
the years as it is faster to give the group the same message.  Even
when I ran a BBS, most would not check it for mail even.

> 3) What can be done to generate renewed interest?

Everyone needs to present a friendly attitude.  Be welcoming and engage
people in conversation.  Activity begets activity which is a bit of a
catch-22, I know.  As WY0X pointed out earlier, friends have a lot of
conversations, and that is the key--friendship.

73, de Nate >>

-- 
 Wireless | Amateur Radio Station N0NB  |  Successfully Microsoft
  Amateur radio exams; ham radio; Linux info @  | free since January 1998.
 http://www.qsl.net/n0nb/   |  "Debian, the choice of
 My Kawasaki KZ-650 SR @| a GNU generation!"
http://www.networksplus.net/n0nb/   |   http://www.debian.org

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Kevin Custer]

I'm not Scott, but maybe I'll do...  
See Below

[EMAIL PROTECTED] wrote:

For Scott:
 
With respect to using the GE MII mobile frame for repeater applications:
 
1. Can  you say categorically that there is sufficient TX/RX shielding 
to prevent any desense  at any power level the conversion is capable 
of operating?


Yes, there is sufficient isolation for single box conversion with 
absolutely no internal desense from the MASTR II Mobile, with the 
exception of the frequency ranges between 223T940/222R340 thru 
224T060/222R460.  Why don't these frequencies work? 



I have built intermittent duty 2 meter repeaters from Mastr II and Micor 
Mobiles with 110 watt PA running at 140+ watts and have seen no sign of 
internal cabinet desense.


2. When these converted mobiles operate with reduced TX power, what 
happens to the output impedance of the TX? Is it still 50 ohms? If 
not, does this affect the physical length of the half wave 
interconnect cables often suggested between the TX and an isolator 
and/or the cavities?


We don't recommend operating a mobile conversion at greatly reduced 
power because the amplifiers are run in Class C, and reducing the power 
will generate spurious emissions.  For the 220 conversion, we totally 
build a new power amplifier as seen in this Micor 220 conversion - GE is 
similar.  See here:

http://www.repeater-builder.com/pix/220micorpa.jpg
http://www.repeater-builder.com/products/ampbd.html

For other bands, we recommend the 45 watt version of the PA which will 
run rated power, continuously.
 3. If the output of the TX is other than 50 ohms as a result of a 
power level change,  does it upset the adjustment of the downstream 
isolator that has been tuned by a tracking generator?


Any time you convert commercial equipment to ham band operation, you 
likely won't have a perfect 50 ohm terminal impedance at the receiver or 
transmitter port, so yes, as all better repeaters builders know, the 
equipment might have to be tuned as a system using custom cabling 
lengths or Z Matchers for optimal performance.


Kevin Custer
Repeater Builder  (the company)

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations? (MVP?)

[Kevin Custer]

skipp025 wrote:
> What about the GE MVP Scott..?  Would the conversion be available 
> and similar for the MVP Mobile? 

Yes, basically it's this conversion:
http://www.repeater-builder.com/ge/mvp/mvpstepbystep.html
With the 220 RF conversions from the Exec II/MVP applied.

You'll notice that Custom MVP is listed on this page:
http://www.repeater-builder.com/rbtip/custombuilt.html

Kevin

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[cruising7388]

 
In a message dated 2/23/2007 4:32:54 P.M. Pacific Standard Time,  
[EMAIL PROTECTED] writes:

as all  better repeaters builders know, the equipment might have to be tuned 
as a  system using custom cabling lengths or Z Matchers for optimal  
performance.



Can you  comment on a difference of opinion regarding how a Z matcher  should 
be adjusted? One school tunes for maximum smoke downstream of the  cavities 
which is the approach I adopt. The other school tunes for minimum  reflected 
SWR between the first cavity and the TX. My academic preference is for  the 
latter, but as a practical matter it's a pain in the buns to do because you  
have 
to account for the line section that the Bird meter adds to the cable.  Beyond 
that, using just a meter, what is it that is actually being measured  since 
it could possibly be a composite of both on-channel energy and and  off-channel 
reflected spurs and harmonics.  
** AOL now offers free 
email to everyone.  Find out more about what's free from AOL at 
http://www.aol.com.

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Kevin Custer]

[EMAIL PROTECTED] wrote:

I'm particularly interested in any shortcomings of the G.E. that are not easily 
overcome.


Repeatability of a band split conversion, out of band (high-band to 222) 
conversion, (where sensitivity is concerned) and tuning stability.


It seems that *some* MASTR II receivers will come out better than 
others.  You can have 3 like receivers in high-band with the same 
high-band sensitivity and tune them 2M and have 3 different sensitivity 
values.  220 is similar, some come out good, some don't.  Anything can 
be made work if messed with long enough.  You usually don't have to mess 
with the MICOR stuff much; it works equally well with each conversion.  
Very very few VHF MICOR receivers that work well originally don't 
convert well, 220 or otherwise.  The UHF MICOR is a whole other story


Here is an overview of my opinion.  This is based on converting 
literally hundreds of receivers, MVP, MASTR II, EXEC II and MICOR:



In my opinion, the only 'real' shortcoming of the GE receivers that 
isn't easily overcome is tuning stability due to their use of ceramic 
tuning capacitors.


Kevin

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Kevin Custer]

[EMAIL PROTECTED] wrote:
In a message dated 2/23/2007 4:32:54 P.M. Pacific Standard Time, 
[EMAIL PROTECTED] writes:


as all better repeaters builders know, the equipment might have to
be tuned as a system using custom cabling lengths or Z Matchers
for optimal performance.

Can you  comment on a difference of opinion regarding how a Z matcher 
should be adjusted? One school tunes for maximum smoke downstream of 
the cavities which is the approach I adopt. The other school tunes for 
minimum reflected SWR between the first cavity and the TX. My academic 
preference is for the latter, but as a practical matter it's a pain in 
the buns to do because you have to account for the line section that 
the Bird meter adds to the cable. Beyond that, using just a meter, 
what is it that is actually being measured since it could possibly be 
a composite of both on-channel energy and and off-channel reflected 
spurs and harmonics. 


I think you answered your own question, however I'll bite

In *most* of the instances where I employed impedance matching between 
the transmitter and first cavity, the place where best return loss and 
least insertion loss was found, is very close to one another -tuning 
wise.  I usually use the maximum smoke approach first and see what I 
have, then go from there.  In my most critical applications, I use 
permanent in-line Bird samplers.  Then, cabling lengths don't change 
because I don't remove the samplers; and you know exactly what you have 
and where


Kevin

RE: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Gary Schafer]

 

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Kevin Custer
Sent: Friday, February 23, 2007 8:34 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

 

[EMAIL PROTECTED] wrote: 

In a message dated 2/23/2007 4:32:54 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:

as all better repeaters builders know, the equipment might have to be tuned
as a system using custom cabling lengths or Z Matchers for optimal
performance.

Can you  comment on a difference of opinion regarding how a Z matcher should
be adjusted? One school tunes for maximum smoke downstream of the cavities
which is the approach I adopt. The other school tunes for minimum reflected
SWR between the first cavity and the TX. My academic preference is for the
latter, but as a practical matter it's a pain in the buns to do because you
have to account for the line section that the Bird meter adds to the cable.
Beyond that, using just a meter, what is it that is actually being measured
since it could possibly be a composite of both on-channel energy and and
off-channel reflected spurs and harmonics.  


I think you answered your own question, however I'll bite

In *most* of the instances where I employed impedance matching between the
transmitter and first cavity, the place where best return loss and least
insertion loss was found, is very close to one another -tuning wise.  I
usually use the maximum smoke approach first and see what I have, then go
from there.  In my most critical applications, I use permanent in-line Bird
samplers.  Then, cabling lengths don't change because I don't remove the
samplers; and you know exactly what you have and where

Kevin
 



Do you use a cable with the bird that makes it a ½ wavelength total line
length when you insert it in line? That should not change things when the
wattmeter/cable are removed.

 

With a PA that does not exhibit a 50 ohm output I would think that it would
be best to tune the Z match for maximum output looking at the antenna
connection (output of the cavities). The reason being if you put the
wattmeter between the Z match and the radio and tune the Z match for minimum
reflected power as noted on the wattmeter then you are tuning the Z match to
match the cavity input to 50 ohms that the wattmeter line section is setup
for. But that is not what the transmitter really is so you end up with a
flat reflected power between the cavity and the transmitter but it does not
match the transmitter.

 

73

Gary  K4FMX

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[mch]

Weren't there some 440 frequencies that had issues, too?

Joe M.

> Kevin Custer wrote:
> 
> I'm not Scott, but maybe I'll do...  
> See Below
> 
> Yes, there is sufficient isolation for single box conversion with
> absolutely no internal desense from the MASTR II Mobile, with the
> exception of the frequency ranges between 223T940/222R340 thru
> 224T060/222R460.  Why don't these frequencies work?
> 

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations? (MVP?)

[Scott Zimmerman]

Yep,

There are several conversions on the RB site for the MVP. They are loosely 
based on the MII conversions. I haven't done many MVP conversions of any 
particular band, but the ones I have done have not had any internal desense 
issues.

Scott

Scott Zimmerman
Amateur Radio Call N3XCC
474 Barnett Road
Boswell, PA 15531
- Original Message - 
From: "skipp025" <[EMAIL PROTECTED]>
To: 
Sent: Friday, February 23, 2007 5:06 PM
Subject: [Repeater-Builder] Re: 220 repeater receiver recommendations? 
(MVP?)


> What about the GE MVP Scott..?  Would the conversion be available
> and similar for the MVP Mobile?
>
> skipp
>
>> "Scott Zimmerman" <[EMAIL PROTECTED]> wrote:
>>
>> With respect to using the GE MII mobile frame for repeater applications:
>>
>> > 1. Can  you say categorically that there is sufficient TX/RX
> shielding to prevent any desense  at any power level the conversion is
> capable of operating?
>>
>> In my experience, yes. In fact, we have had several repeaters that
> the sensitivity actually gets BETTER with the transmitter active. (due
> to the correct 50 impedance being applied to the TX port of the
> duplexer) The only problems we have had with in-cabinet de-sense go
> back to issues with a transmitter multiple getting into a sensitive
> spot of the receiver. This is a well known phenomenon on UHF Mastr
> II's, but it also happens on converted 220 micors and MII's. I have
> been wanting to write up this research for some time. I will try to do
> it as soon as I can.
>>
>> 2. When these converted mobiles operate with reduced TX power, what
> happens to the output impedance of the TX? Is it still 50 ohms? If
> not, does this affect the physical length of the half wave
> interconnect cables often suggested between the TX and an isolator
> and/or the cavities?
>>
>> As others have stated, it may not be *exactly* 50j0, but it's close
> enough. Realize that most of the "50 ohm" coax cable actually spec'd
> to be 52 ohm nominal!! I would think that the cable being 2 ohms off
> would be more detriment than the 50ohm designed output / input
> impedance that might move fractions of an ohm in impedance due to
> being tuned a few MHz from it's design frequency. If you want to get
> that picky, should a PA's output be tuned for 50 ohms when the
> frequency is changed from let's say 155.xx to 158.xxx? I would think
> that if the designers would have thought the port impedance to be that
> critical, they would have made provisions to adjust it.
>>
>> As far as our 220 modifications go; we use a M57774 power module. We
> DO NOT modify/retune the VHF pa to 220. If we did, we might run into
> design issues where impedance problems might rare their ugly head. We
> just use an off-the-shelf solution that works well.
>>
>> If not, does this affect the physical length of the half wave
> interconnect cables often suggested between the TX and an isolator
> and/or the cavities?
>>
>> 3. If the output of the TX is other than 50 ohms as a result of a
> power level change,  does it upset the adjustment of the downstream
> isolator that has been tuned by a tracking generator?
>>
>> Can't say. I have no experience. I will defer this question to others.
>>
>> Scott
>>
>> Scott Zimmerman
>> Amateur Radio Call N3XCC
>> 612 Barnett Rd
>> Boswell, PA 15531
>>
>>   - Original Message - 
>>   From: [EMAIL PROTECTED]
>>   To: Repeater-Builder@yahoogroups.com
>>   Sent: Friday, February 23, 2007 2:24 PM
>>   Subject: Re: [Repeater-Builder] Re: 220 repeater receiver
> recommendations?
>>
>>
>>
>>   For Scott:
>>
>>   With respect to using the GE MII mobile frame for repeater
> applications:
>>
>>   1. Can  you say categorically that there is sufficient TX/RX
> shielding to prevent any desense  at any power level the conversion is
> capable of operating?
>>
>>   2. When these converted mobiles operate with reduced TX power,
> what happens to the output impedance of the TX? Is it still 50 ohms?
> If not, does this affect the physical length of the half wave
> interconnect cables often suggested between the TX and an isolator
> and/or the cavities?
>>
>>   3. If the output of the TX is other than 50 ohms as a result of a
> power level change,  does it upset the adjustment of the downstream
> isolator that has been tuned by a tracking generator?
>>
>>   Tks
>>
>>   Bruce
>>   K7IJ
>>
>>
>>
>>
>>   In a message dated 2/22/2007 7:02:38 P.M. Pacific Standard Time,
> [EMAIL PROTECTED] writes:
>> Ken,
>>
>> We not only do complete repeaters, we can custom build just
> about anything you want or need. We can simply build a rock-solid
> high-quality 220 receiver for you. We have done several receivers in
> the past that are rack mountable in a 2 unit rack space. I have a GE
> mastr II receiver that I am just finishing up. It came out looking so
> nice that I am going to take pictures as a show piece. Micor receivers
> would be VERY similar in construction.
>>
>> In my opinion, 2 things:
>>
>> 1. A Micor makes a 

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[cruising7388]

 
In a message dated 2/23/2007 6:15:19 P.M. Pacific Standard Time,  
[EMAIL PROTECTED] writes:

Do you use a cable  with the bird that makes it a ½ wavelength total line 
length when you insert  it in line? That should not change things when the 
wattmeter/cable are  removed. 



I'm not sure I understand what you are saying. The Bird constitutes part of  
the line section and if you remove it after tuning with the z match, haven't 
you  effectively changed the length of the line?
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Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Scott Zimmerman]

Yep. Best bet for a GE mobile on UHF is order your RX crystals high-side 
injection for all freq's.

Scott

Scott Zimmerman
Amateur Radio Call N3XCC
474 Barnett Road
Boswell, PA 15531
- Original Message - 
From: "mch" <[EMAIL PROTECTED]>
To: 
Sent: Friday, February 23, 2007 9:10 PM
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?


> Weren't there some 440 frequencies that had issues, too?
>
> Joe M.
>
>> Kevin Custer wrote:
>>
>> I'm not Scott, but maybe I'll do...  
>> See Below
>>
>> Yes, there is sufficient isolation for single box conversion with
>> absolutely no internal desense from the MASTR II Mobile, with the
>> exception of the frequency ranges between 223T940/222R340 thru
>> 224T060/222R460.  Why don't these frequencies work?
>> 
>
>
>
>
>
> Yahoo! Groups - Join or create groups, clubs, forums & communities. 
> Links
>
>
>
>
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.446 / Virus Database: 268.18.3/699 - Release Date: 2/23/2007 
> 1:26 PM
>
> 

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations? (Z-Matcher)

[cruising7388]

 
In a message dated 2/23/2007 6:36:24 P.M. Pacific Standard Time,  
[EMAIL PROTECTED] writes:

In my  most critical applications, I use permanent in-line Bird samplers.  
Then,  cabling lengths don't change because I don't remove the samplers; and 
you 
know  exactly what you have and where





If you can afford to leave Bird 4275s in your cables, please be sure that  my 
name is correctly
spelled in your will. 
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Re: [Repeater-Builder] 220 repeater receiver recommendations?

[George Henry]

- Original Message - 
From: "Nate Duehr" <[EMAIL PROTECTED]>
To: 
Sent: Friday, February 23, 2007 2:48 PM
Subject: Re: [Repeater-Builder] 220 repeater receiver recommendations?


[snip]

> 
> Currently running a Kendecomm.  Hate it.
> 
> Pots are squirrelly (low quality) for any possible adjustment, the
> thing is impossible to work on in the rack - have to pull it out,
> remove a billion screws, and put it back in -- it won't stay on
> frequency... and it's installed in a temperature-controlled climate,
> and the meters on the front have had something weirdly wrong with them
> for years... trying to decipher them into useful information -- ain't
> happenin'.
> 
> I will be happy to pitch it off the side of something very very tall
> as soon as...
> 
> We're replacing it with a Mastr II conversion -- that supposedly I'm
> doing -- well, I got the first one done and it's receiver is very
> deaf... (starts to hear signal at 2uV -- no, not .2uV... 2!!
> g)...
> 
[snip]

Maybe it grew whiskers?   ;-)

George, KA3HSW / WQGJ413

[Repeater-Builder] Problem mit RSS für Motorola MX 2000 VHF und MX 3000 UHF

[alpen_puma]

Hallo zusammen
Ich habe eine Frage was die Programmierung der beiden Fug`s 
anbelangt.
Die Software RSS für MX 3010 / 3013 geht nicht und die RSS 02.04.00
sagt mir nach dem auslesen der Geräte folgende Meldung:
MX 3000: Not supported special Product, SP Number = 150
MX 2000: Not supported special Product; SP Number = 148
Kann eventuell einer von euch mir da weiterhelfen?
Dies währe enorm erfreulich für mich.
Ich danke euch im voraus und einen schönen Abend noch.
MFG Role

This text is translated with Google from German to English. 
Therefore you excuse ask my question: -) Hello together I has a 
question which the programming of the two joins `s concerned. The 
software RSS for MX 3010/3013 does not go and the RSS 02.04.00 says 
to to me to select the devices the following message: MX 3000: 
Emergency supported special Product, SP NUMBER = 150 MX 2000: 
Emergency supported special Product; SP NUMBER = 148 
Can possibly help one of you there me? This lasts enormously 
pleasing for me. I thank you in advance and a beautiful evening 
still. MFG Role

RE: [Repeater-Builder] Re: 220 repeater receiver recommendations?

[Gary Schafer]

 

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Friday, February 23, 2007 10:23 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?

 

In a message dated 2/23/2007 6:15:19 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:

Do you use a cable with the bird that makes it a ½ wavelength total line
length when you insert it in line? That should not change things when the
wattmeter/cable are removed.

I'm not sure I understand what you are saying. The Bird constitutes part of
the line section and if you remove it after tuning with the z match, haven't
you effectively changed the length of the line?





There is a chart in the bird manual that tells you what length of jumper
cable to use with the bird meter for each frequency band so that the
combination of the jumper cable length and the line section of the meter
equals ½ wavelength._,Then when you insert that combination into a circuit
you are inserting a ½ wavelength and whatever impedance the circuit may
happen to be, it will be the same at the other end of the bird/cable. After
tune up you can remove the meter and jumper and the circuit tuning will
remain the same.

 

But you still can’t place the meter between the transmitter and the Z match
and tune for minimum reflected power if the transmitter output is not 50
ohms as the meters line section is set up to read minimum reflected power
only when it sees 50 ohms. You can adjust the Z match to show 50 ohms to the
wattmeter but if the transmitter output is not 50 ohms then there will be a
mismatch and you will not have tuned the Z match to the transmitter
impedance.

73

Gary  K4FMX

Re: [Repeater-Builder] 440-450 band plan (The normal North vs So Cal :-)

[Mike Morris WA6ILQ]

At 03:27 PM 02/23/07, you wrote:
>Hi Mike,
>
>Even more fun is the frequent band openings.  One repeater in the
>SF Bay Area will lock up its reverse co-channel So Cal machine. Both
>have no practical time-out timers. Happens more than a few times
>a month... sometimes a few times in one week.

Yep.  All the more reason to require PL'd inputs and make sure that
systems don't have compatible PL tones with the one on the reverse...

>I can't help it if you guys are "upside down"...  :-)

Nh, YOU'RE upside down !!! (Grin)

Mike

>cheers,
>s.
>
> > Careful there - NorCal is repeater-input high, and repeater-output
> > low, SoCal is the reverse.  Dividing line is the Santa Maria River.
> > There are valid arguments for each method... Makes it lots of fun
> > for the guys in the middle ... they have to pick the frequencies
> > carefully to avoid lockups and a system output capturing someone
> > elses input.

Re: [Repeater-Builder] Re: 220 repeater receiver recommendations? (Z-Matcher)

[cruising7388]

 
In a message dated 2/23/2007 6:36:24 P.M. Pacific Standard Time,  
[EMAIL PROTECTED] writes:

In  regards to the question of a wattmeter adding length to a cable, in 
places  where I use Z-matchers, I actually leave an N-barrel connector in line 
that 
 can be removed for inserting the wattmeter without adding any cable.  So  
when you put that barrel back, you're pretty darn close.  ...




Not necessarily. At low band VHF frequencies, you could probably discount  
the error produced
by the Bird. But in high band VHF and up, it becomes progressively more  
critical. The constant is the physical length of the Bird line section which is 
 3 
13/16 inches but including the terminating N connectors, the length is 5 1/8  
inches. This is where it gets interesting. The line section is air line and 
has  a
different velocity constant than RG142 or RG214. 
 
Section 3-35 states:
 
Using  the THRULINE you will be inserting a 4 inch length of 
50 ohm air line
and  the load on the transmitter will be changed from its 
original condition
without  the THRULINE.
 
 
But Section 3-40 states:
 
Since  the length of line between a mismatched load and the 
source transforms
the  impedance of the load as seen at the source, line length 
now becomes
critical.  If the adjustments for maximum power transfer were 
made with the
Model  43  in place, removing it shortens the line by four 
inches, plus  two
connectors.   (emphasis mine).
 
 
So one section says to allow 4 inches while the other section says to allow  
5 1/8 inches.
Go figure. In any event, the use of a single barrel would miss the mark at  2 
meters and
above. 
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Re: [Repeater-Builder] 440-450 band plan (The normal North vs So Cal :-)

[DCFluX]

PL is no cure for interference or desence, it just hides it until
someone actually tries to use the repeater.

> Yep.  All the more reason to require PL'd inputs and make sure that
> systems don't have compatible PL tones with the one on the reverse...

Re: [Repeater-Builder] 220 repeater receiver recommendations?

[no6b]

At 2/23/2007 12:48, you wrote:
>On 2/22/07, Ken Harrison <[EMAIL PROTECTED]> wrote:
> > Our group is in need of replacing the receiver on our 220 box and I
> > wanted to solicit some opinions from the group.
>
> > What are you using and are you happy with it?  Would you buy any
> > particular one again?  Why or why not.
>
>Currently running a Kendecomm.  Hate it.

Welcome to the club!


>Pots are squirrelly (low quality) for any possible adjustment, the

Yup.  Replaced all of them in ours.

>thing is impossible to work on in the rack - have to pull it out,
>remove a billion screws, and put it back in -- it won't stay on
>frequency... and it's installed in a temperature-controlled climate,
>and the meters on the front have had something weirdly wrong with them
>for years... trying to decipher them into useful information -- ain't
>happenin'.

One thing you can do with the RX is to ditch their bilevel squelch & 
retrofit a Micor squelch.  The Kendecom squelch uses signal strength, not 
noise, to control their bilevel squelch.  Problem with that is that the 
sig. strength is detected at the FIRST IF, NOT after the 455 kHz filter, so 
if you have any significant adjacent-channel signals, they can mess up the 
bilevel squelch & cause chopping.

Even after installing the Micor squelch, there appears to be a problem with 
strong adjacent-channel signals (2 meters @ 15 kHz spacing) causing the 
squelch to close.  I think it's due to excessive 1st IF gain, causing AMing 
in the IF.


>I will be happy to pitch it off the side of something very very tall
>as soon as...
>
>We're replacing it with a Mastr II conversion -- that supposedly I'm
>doing -- well, I got the first one done and it's receiver is very
>deaf... (starts to hear signal at 2uV -- no, not .2uV... 2!!
>g)...
>
>So I'm struggling through trying to figure out what went wrong...

One of our local coordinating committee members had a similar problem 
converting a VHF HB MVP to 220.  I think he said he ended up with a 
passband response in the front-end helicals that had excessive ripple, as 
if the phasing between helical sections got messed up.  I'm going to 
undertake that task soon & will see if I have similar problems.

Bob NO6B