Re: [Repeater-Builder] An advocate for a little audio compression

[Nate Duehr]

On Aug 9, 2009, at 9:07 PM, skipp025 wrote:

> re: An advocate for a little audio compression.
>
> Yeah, I know a decent number of you are in-stone
> same-in to same-out repeater audio levels types.
>
> However, I've changed my opinion.
>

You're a brave man to say it, Skipp.

Here's my problem with it.  Let's just say there's a very large linked  
repeater system that decided MANY years ago that they could "fix" the  
incoming audio from their IRLP link from BADLY CONFIGURED IRLP NODES  
by adding a commercial compressor-limiter in-line.

I won't say who or where, since I like the folks running it and have  
ZERO beefs with them.  I just need to use them as an example of where  
compression/limiting is BAD NEWS.

However, let's also just say that I've called them from MULTIPLE IRLP  
nodes I've set up PERFECTLY with a service monitor and swept for audio  
response, and they ALWAYS complain about whatever it is they're  
hearing on their end -- after their compressor-limiter.

Hey guess what folks.  The audio left here JUST FINE... someone on  
that end decided to muck around with it.  Not much I can do about that.

What does this phenomenon actually lead to?  I don't know.  Maybe an  
idea below...

I know my nodes are done right, and I know they have a LOT of other  
nodes connected to them that sound like ass so they tried to fix it.

But, instead of asking those folks to fix their nodes, they tried a  
fix on their end, and broke things for those of us sending proper  
levels and audio.

If they'd put in a way to TURN IT OFF, they'd hear what a properly set  
up IRLP node is supposed to sound like.

Do I care?  Not really.  But the experience of that problem over the  
years, has just entrenched me further in the "what comes in is what  
goes out" camp.

Do I realize that the vast majority of folks setting up IRLP nodes  
don't bother setting levels CORRECTLY to a network standard?  Oh heck,  
yes.  I rant about that at least once a year on the IRLP list... to  
mostly deaf ears.

So I say, sure... compress away on a local repeater only.  But please  
keep the compressed audio the hell away from outbound links to  
others... and away from the incoming link audio too.  And always  
provide a way for the USERS to turn it off, just to see if it's having  
a bad effect.

Seems reasonable, doesn't it?

I think that's a fair opinion to all.

Compress the snot out of local traffic if you want... but please send  
the rest of us something that sounds like what your users put in out  
any links, especially IP-based ones.

Otherwise you run the risk of really bugging those of us who DID set  
levels and test audio, by creating a new problem the users on the far  
end think is OUR problem.

What do you think Skipp?  Is that a fair point to make?  Links to  
other people's systems shouldn't include compression.

Now... the reality is... some repeaters do it anyway... hard to stop  
it from going out.  I can almost always tell ya when someone's on a  
MODERN (not MICOR) Motorola repeater by listening to their audio  
coming out of my IRLP node(s).  In fact, with the audio set up  
correctly on an IRLP node, it's downright easy to tell there's a Bat- 
Wing somewhere on the other end of the link.

--
Nate Duehr, WY0X
n...@natetech.com

[Repeater-Builder] Micor cos question

[Nick]

I have a micor Station , I did  the mod for the cos on the audio sq board . I 
have 9.6v no signal , with signal 0 volts. I need o volts no signal and 5 volts 
or more for signal. I did the invert logic mod , with the 10 k npn 2n 
transiter not enough voltage less than 1 volt. Any Ideas ?

Re: [Repeater-Builder] An advocate for a little audio compression

[Paul Plack]

Skipp, I generally agree, but it's not the fault of the user's voice. It's a 
lack of training in mic technique, sometimes combined with audio circuits that 
aren't easily user-accessible. Compression on the repeater eliminate's the 
user's need to get things right at the source, and one day, he's going to need 
to operate simplex.

I've worked with broadcast compressors for many years, and agree they could 
play a useful role in repeater audio chains. But I always wanted to design one 
that was a little different, and digital control of an analog signal path seems 
like a good candidate.

Specifically, I'd like to have something like a compressor with very fast 
attack and infinitely long release, immediately dropping gain as needed to 
accommodate voice peaks, but not releasing until COS dropped. This would 
essentially set the audio gain individually for each user at the start of a 
transmission, without any ongoing compression to create the obnoxious "pumping" 
artifact we all know and hate.

The downsides would be additional background noise before the first syllable, 
and difficulty in distinguishing users with low audio from users with 
inadequate signal strength. Both would feature increased background noise as a 
symptom. Then again, IRLP users hand out S-meter reports from a thousand miles 
away, so maybe it doesn't matter...(sigh)

Just running the audio gain 6-10 dB hotter into a fast limiter still allows 
great disparity in perceived loudness, but at least the guys with low audio can 
be heard.

73,
Paul, AE4KR

  - Original Message - 
  From: skipp025 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Sunday, August 09, 2009 9:07 PM
  Subject: [Repeater-Builder] An advocate for a little audio compression


...a number of operators don't seem to have voices that 
  drive their radios with adequate audio...Consider 6 to 10dB of audio 
compression in your repeater system...


  . 

  

[Repeater-Builder] Re: An advocate for a little audio compression

[Laryn Lohman]

Me too.  When the ACC RC850 audio levels are adjusted properly, the on-board 
AGC gives around the 6-10db of AGC you describe.  I believe it works pretty 
well and is not annoying.

I used the term  intentionally.  In the 850 the ratio is around 2:1, and 
moderately slow to release.  If release is too fast, noise increases in level 
too fast and quickly becomes a more prominent part of the audio.  The term 
 implies a quicker release time than AGC does.

There was a discussion of this topic some time ago, and somewhere I have some 
of the posts stored on this computer.  I'll try to find them if there's 
interest.

Laryn K8TVZ

[Repeater-Builder] Re: An advocate for a little audio compression

[skipp025]

Let me be a little more specific and I'm sure the following 
will stir up the normal bees nest I seem to always find. 

I enjoy bringing up the average audio level using the 
transmit limiter. In some cases that circuit is an agc 
type and in some it's a straight forward limiter. I don't 
normally find a reason to add an external device when what 
hardware is often included is quite useful. 

http://en.wikipedia.org/wiki/Dynamic_range_compression 

s.


> "JOHN MACKEY"  wrote:
>
> what equipment have you used to do the compression?
> 
> -- Original Message --
> Received: Sun, 09 Aug 2009 08:07:45 PM PDT
> From: "skipp025" 
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] An advocate for a little audio compression
> 
> > re: An advocate for a little audio compression. 
> > 
> > Yeah, I know a decent number of you are in-stone 
> > same-in to same-out repeater audio levels types. 
> > 
> > However, I've changed my opinion. 
> > 
> > A number of operators don't seem to have voices that 
> > drive their radios with adequate audio and I always 
> > seem to be reaching for the volume control. 
> > 
> > So I've started adding a modest amount of audio 
> > compression to a few repeaters and the difference is 
> > a very pleasant and well received change. 
> > 
> > Consider 6 to 10dB of audio compression in your repeater 
> > system if you're constantly reaching for the volume 
> > control while listening to more than one person 
> > talk at different levels. I'm experimenting with higher 
> > and even dynamic audio compression values but for most 
> > situations the above values seem to work well. 
> > 
> > If you're not sure how to add a bit of audio compression 
> > to your specific system... wouldn't be hard to describe 
> > it as in most cases the hardware is already in place. 
> > 
> > Transparent or flat through repeater audio can be made 
> > louder without causing the world to come to screeching 
> > halt. 
> > 
> > cheers, 
> > skipp 
> > 
> >
>

Re: [Repeater-Builder] An advocate for a little audio compression

[John Sichert]

I use a Behringer MDX2200.
I think it has been discontinued for some time. It has all the hot 
stuff you want. Compressor, limiter, and a noise gate. It doesn't 
take very long to tune it in. If you don't have it right, you'll know it...

Looks like they are going for about $75 on eSlay.

John



At 11:10 PM 8/9/2009, you wrote:
>what equipment have you used to do the compression?
>
>-- Original Message --
>Received: Sun, 09 Aug 2009 08:07:45 PM PDT
>From: "skipp025" 
>To: Repeater-Builder@yahoogroups.com
>Subject: [Repeater-Builder] An advocate for a little audio compression
>
> > re: An advocate for a little audio compression.
> >
> > Yeah, I know a decent number of you are in-stone
> > same-in to same-out repeater audio levels types.
> >
> > However, I've changed my opinion.
> >
> > A number of operators don't seem to have voices that
> > drive their radios with adequate audio and I always
> > seem to be reaching for the volume control.
> >
> > So I've started adding a modest amount of audio
> > compression to a few repeaters and the difference is
> > a very pleasant and well received change.
> >
> > Consider 6 to 10dB of audio compression in your repeater
> > system if you're constantly reaching for the volume
> > control while listening to more than one person
> > talk at different levels. I'm experimenting with higher
> > and even dynamic audio compression values but for most
> > situations the above values seem to work well.
> >
> > If you're not sure how to add a bit of audio compression
> > to your specific system... wouldn't be hard to describe
> > it as in most cases the hardware is already in place.
> >
> > Transparent or flat through repeater audio can be made
> > louder without causing the world to come to screeching
> > halt.
> >
> > cheers,
> > skipp
> >
> >
>
>
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

Re: [Repeater-Builder] An advocate for a little audio compression

[JOHN MACKEY]

what equipment have you used to do the compression?

-- Original Message --
Received: Sun, 09 Aug 2009 08:07:45 PM PDT
From: "skipp025" 
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] An advocate for a little audio compression

> re: An advocate for a little audio compression. 
> 
> Yeah, I know a decent number of you are in-stone 
> same-in to same-out repeater audio levels types. 
> 
> However, I've changed my opinion. 
> 
> A number of operators don't seem to have voices that 
> drive their radios with adequate audio and I always 
> seem to be reaching for the volume control. 
> 
> So I've started adding a modest amount of audio 
> compression to a few repeaters and the difference is 
> a very pleasant and well received change. 
> 
> Consider 6 to 10dB of audio compression in your repeater 
> system if you're constantly reaching for the volume 
> control while listening to more than one person 
> talk at different levels. I'm experimenting with higher 
> and even dynamic audio compression values but for most 
> situations the above values seem to work well. 
> 
> If you're not sure how to add a bit of audio compression 
> to your specific system... wouldn't be hard to describe 
> it as in most cases the hardware is already in place. 
> 
> Transparent or flat through repeater audio can be made 
> louder without causing the world to come to screeching 
> halt. 
> 
> cheers, 
> skipp 
> 
> 

[Repeater-Builder] An advocate for a little audio compression

[skipp025]

re: An advocate for a little audio compression. 

Yeah, I know a decent number of you are in-stone 
same-in to same-out repeater audio levels types. 

However, I've changed my opinion. 

A number of operators don't seem to have voices that 
drive their radios with adequate audio and I always 
seem to be reaching for the volume control. 

So I've started adding a modest amount of audio 
compression to a few repeaters and the difference is 
a very pleasant and well received change. 

Consider 6 to 10dB of audio compression in your repeater 
system if you're constantly reaching for the volume 
control while listening to more than one person 
talk at different levels. I'm experimenting with higher 
and even dynamic audio compression values but for most 
situations the above values seem to work well. 

If you're not sure how to add a bit of audio compression 
to your specific system... wouldn't be hard to describe 
it as in most cases the hardware is already in place. 

Transparent or flat through repeater audio can be made 
louder without causing the world to come to screeching 
halt. 

cheers, 
skipp 

Re: [Repeater-Builder] Re: 2M Vertical Dipoles

[AJ]

Comtech I believe has the modeling for antenna side mounting from tower and
it's affect on gain...

On Sun, Aug 9, 2009 at 7:14 PM,  wrote:

>
>
> At 8/9/2009 16:41, you wrote:
> > What was the spacing between the tower legs at the mounting location of
> > the dipoles in your model?
>
> No tower. Only the rooftop-mounted mast & 4 dipoles, which is what I was
> using at the time.
>
> Bob NO6B
>
>  
>

Re: [Repeater-Builder] Re: 2M Vertical Dipoles

[no6b]

At 8/9/2009 16:41, you wrote:
>  What was the spacing between the tower legs at the mounting location of 
> the dipoles in your model?

No tower.  Only the rooftop-mounted mast & 4 dipoles, which is what I was 
using at the time.

Bob NO6B

Re: [Repeater-Builder] 2M Vertical Dipoles

[Mike Morris WA6ILQ]

Anyone have any info on a Regency Micro-Comm U10R ?

Especially the pinout of the 15-pin Molex plug?

I have one here and was wondering if it was worth resurrecting.

Mike WA6ILQ

Re: [Repeater-Builder] 2M Vertical Dipoles

[Chuck Kelsey]

I was speaking of pointing all the elements in the same direction - away from 
the tower, all mounted on the same leg. You should see good gain for about 180 
degrees in the direction the elements are pointed. Hard to say whet you'll get 
off the back of the tower, but it might not be as bad as you think. Sometime 
you just have to try it.

Chuck
WB2EDV



  - Original Message - 
  From: Jim Cicirello 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Sunday, August 09, 2009 7:51 PM
  Subject: RE: [Repeater-Builder] 2M Vertical Dipoles





  Chuck, Would that be with the dipoles all pointed in the same direction, of 
set up so they face different directions for Omni reception. I picked up an 
almost new DB224 but no mast so I am following this thread with interest.

  73 JIM  KA2AJH

   

  From: Repeater-Builder@yahoogroups.com 
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey
  Sent: Sunday, August 09, 2009 7:43 PM
  To: Repeater-Builder@yahoogroups.com
  Subject: Re: [Repeater-Builder] 2M Vertical Dipoles

   



  That will work well to favor one area.

  Chuck
  WB2EDV

RE: [Repeater-Builder] 2M Vertical Dipoles

[Jim Cicirello]

Chuck, Would that be with the dipoles all pointed in the same direction, of
set up so they face different directions for Omni reception. I picked up an
almost new DB224 but no mast so I am following this thread with interest.

73 JIM  KA2AJH

 

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey
Sent: Sunday, August 09, 2009 7:43 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] 2M Vertical Dipoles

 

  

That will work well to favor one area.

Chuck
WB2EDV

- Original Message - 
From: "MCH" mailto:mch%40nb.net> >
To: mailto:Repeater-Builder%40yahoogroups.com> >
Sent: Sunday, August 09, 2009 7:40 PM
Subject: Re: [Repeater-Builder] 2M Vertical Dipoles

> DOH! Let me rephrase that...
>
> Lots of comments on the omnidirectional pattern which I suggested might
> not work well.
>
> Any comments on having the elements on one side of the tower right on
> the leg?
>
> Joe M.
>
> MCH wrote:
>> Lots of comments on the unidirectional pattern which I suggested might
>> not work well.
>>
>> Any comments on having the elements on one side of the tower right on
>> the leg?
>>
>> Joe M.
>>
>> n...@no6b.com   wrote:
>>> At 8/9/2009 05:47, you wrote:
>>>
>>>
 As frequency decreases, so does the importance of keeping the dipoles
 exactly above one another. This is why you can get away with mounting 
 the
 bays of a LB array around a smaller tower (like Rohn 25) and still have
 very good omni-directional performance. Positioning the bays around a
 central supporting mast of a UHF array creates considerable pattern
 distortion and gain is lost.
>>> I once modeled this arrangement in NEC-Win: the resulting pattern looked
>>> like a warped pancake. On-horizon gain was all over the place.
>>>
>>> Bob NO6B
>>>
>>>
>>>
>>> 
>>>
>>>
>>>
>>> Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>
>>
>> 
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>

Re: [Repeater-Builder] 2M Vertical Dipoles

[Chuck Kelsey]

That will work well to favor one area.

Chuck
WB2EDV



- Original Message - 
From: "MCH" 
To: 
Sent: Sunday, August 09, 2009 7:40 PM
Subject: Re: [Repeater-Builder] 2M Vertical Dipoles


> DOH! Let me rephrase that...
>
> Lots of comments on the omnidirectional pattern which I suggested might
> not work well.
>
> Any comments on having the elements on one side of the tower right on
> the leg?
>
> Joe M.
>
> MCH wrote:
>> Lots of comments on the unidirectional pattern which I suggested might
>> not work well.
>>
>> Any comments on having the elements on one side of the tower right on
>> the leg?
>>
>> Joe M.
>>
>> n...@no6b.com wrote:
>>> At 8/9/2009 05:47, you wrote:
>>>
>>>
 As frequency decreases, so does the importance of keeping the dipoles
 exactly above one another.  This is why you can get away with mounting 
 the
 bays of a LB array around a smaller tower (like Rohn 25) and still have
 very good omni-directional performance.  Positioning the bays around a
 central supporting mast of a UHF array creates considerable pattern
 distortion and gain is lost.
>>> I once modeled this arrangement in NEC-Win: the resulting pattern looked
>>> like a warped pancake.  On-horizon gain was all over the place.
>>>
>>> Bob NO6B
>>>
>>>
>>>
>>> 
>>>
>>>
>>>
>>> Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>
>>
>> 
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>

[Repeater-Builder] Re: 2M Vertical Dipoles

[wa9zzu]

 What was the spacing between the tower legs at the mounting location of the 
dipoles in your model? 
Allan Crites WA9ZZU

-- In Repeater-Builder@yahoogroups.com, n...@... wrote:
>
> At 8/9/2009 05:47, you wrote:
> 
> 
> >As frequency decreases, so does the importance of keeping the dipoles 
> >exactly above one another.  This is why you can get away with mounting the 
> >bays of a LB array around a smaller tower (like Rohn 25) and still have 
> >very good omni-directional performance.  Positioning the bays around a 
> >central supporting mast of a UHF array creates considerable pattern 
> >distortion and gain is lost.
> 
> I once modeled this arrangement in NEC-Win: the resulting pattern looked 
> like a warped pancake.  On-horizon gain was all over the place.
> 
> Bob NO6B
>

Re: [Repeater-Builder] 2M Vertical Dipoles

[MCH]

DOH! Let me rephrase that...

Lots of comments on the omnidirectional pattern which I suggested might
not work well.

Any comments on having the elements on one side of the tower right on
the leg?

Joe M.

MCH wrote:
> Lots of comments on the unidirectional pattern which I suggested might 
> not work well.
> 
> Any comments on having the elements on one side of the tower right on 
> the leg?
> 
> Joe M.
> 
> n...@no6b.com wrote:
>> At 8/9/2009 05:47, you wrote:
>>
>>
>>> As frequency decreases, so does the importance of keeping the dipoles 
>>> exactly above one another.  This is why you can get away with mounting the 
>>> bays of a LB array around a smaller tower (like Rohn 25) and still have 
>>> very good omni-directional performance.  Positioning the bays around a 
>>> central supporting mast of a UHF array creates considerable pattern 
>>> distortion and gain is lost.
>> I once modeled this arrangement in NEC-Win: the resulting pattern looked 
>> like a warped pancake.  On-horizon gain was all over the place.
>>
>> Bob NO6B
>>
>>
>>
>> 
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 

Re: [Repeater-Builder] 2M Vertical Dipoles

[Chuck Kelsey]

If you want to get better omni coverage, you'll need to attach the dipoles 
to a mast and use stand-off brackets to hold it away from the tower. The 
pattern will still be affected by the tower, but not as drastically.

Chuck
WB2EDV


- Original Message - 
From: "MCH" 
To: 
Sent: Sunday, August 09, 2009 7:33 PM
Subject: Re: [Repeater-Builder] 2M Vertical Dipoles


> Lots of comments on the unidirectional pattern which I suggested might
> not work well.
>
> Any comments on having the elements on one side of the tower right on
> the leg?
>
> Joe M.
>
> n...@no6b.com wrote:
>> At 8/9/2009 05:47, you wrote:
>>
>>
>>> As frequency decreases, so does the importance of keeping the dipoles
>>> exactly above one another.  This is why you can get away with mounting 
>>> the
>>> bays of a LB array around a smaller tower (like Rohn 25) and still have
>>> very good omni-directional performance.  Positioning the bays around a
>>> central supporting mast of a UHF array creates considerable pattern
>>> distortion and gain is lost.
>>
>> I once modeled this arrangement in NEC-Win: the resulting pattern looked
>> like a warped pancake.  On-horizon gain was all over the place.
>>
>> Bob NO6B
>>
>>
>>
>> 
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>

Re: [Repeater-Builder] 2M Vertical Dipoles

[MCH]

Lots of comments on the unidirectional pattern which I suggested might 
not work well.

Any comments on having the elements on one side of the tower right on 
the leg?

Joe M.

n...@no6b.com wrote:
> At 8/9/2009 05:47, you wrote:
> 
> 
>> As frequency decreases, so does the importance of keeping the dipoles 
>> exactly above one another.  This is why you can get away with mounting the 
>> bays of a LB array around a smaller tower (like Rohn 25) and still have 
>> very good omni-directional performance.  Positioning the bays around a 
>> central supporting mast of a UHF array creates considerable pattern 
>> distortion and gain is lost.
> 
> I once modeled this arrangement in NEC-Win: the resulting pattern looked 
> like a warped pancake.  On-horizon gain was all over the place.
> 
> Bob NO6B
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 

[Repeater-Builder] Replacement Caps. for Motorola Micor Pwr supplies

[kh6jkg]

Does anyone have a source for these capacitors, 
Which are used in Motorola Micor power supplies?

TPN1106A? C1006-C1009? 2000 mfd, 100V @10%
C1012, C1013? 17,500 mfd 20V @10%

TPN1110A???C1? 6 mfd @ 660v
C2-9 17,500 mfd 20v @ 10%

TPN1151A? C1-2? 8000 mfd 35v @ 10%

73's,??? Jim?Kh6jkg.

RE: [Repeater-Builder] Sinclair R2B12 duplexer

[Eric Lemmon]

Martin,

The best place to get that information is from the company that built it.
Contact Sinclair Technologies at 800-263-3275.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of cruizzer77
Sent: Saturday, August 08, 2009 12:54 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Sinclair R2B12 duplexer

  

Does anyone have technical info (i.e. tech drawings) or inside pics of these
duplexers? I wonder how they do the shortening as there can't be a 1/4 wave
resonator for 2m inside this 19" box...

Regards
Martin

RE: [Repeater-Builder] 2M Vertical Dipoles

[Doug Rehman]

It was indeed the Telewave ANT-150D that I had seen; I just found the ad in
the August QST.

 

Unfortunately, the Telewave is out of the budget for this project though. 

 

Is anyone familiar with the Antenex YDA1364? (4 dipole array)
http://www.ameradio.com/product/9449/description.html Has anyone done
business with ameradio.com? Their price is $217; Hutton's is $309.

 

I only need 2 dipoles, but it looks like the harness could be easily split
for two sets of 2 dipoles. (They offer a 2 dipole array for the higher
frequency range, but not for the range covering 2 meters.)

 

Since I need omni coverage on a rotating mast, maybe putting two elements
back to back would work (like the UHF DB antennas use for each bay)?

 

Doug K4AC

 

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Edmund F Leavitt
Sent: Saturday, August 08, 2009 10:49 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] 2M Vertical Dipoles

 

 Do you recall if it was a dipole or folded dipole?


Edmund Leavitt Ph: 253 582-5034 
Ham / MARS / Federal K7EFL / AFA0AH / KPS654 
Lakewood, WA USNG: 10TET36292223

Re: [Repeater-Builder] Re: Narrow banding question

[no6b]

At 8/8/2009 21:33, you wrote:
>As have many other parts of the country - to 12.5 kHz on 440.
>
>But, when you say narrowbanding, are you talking the actual users
>switching from NBFM (16.0 kHz BW) to SNFM (11.0 kHz BW) or are you just
>talking about the bandplan going from 25.0 kHz channels to 20.0 kHz
>channels and everyone is still using NBFM as they have for the past
>nearly 40 years?

The latter.  Not narrowbanding at all, just an attempt to more effectively 
utilize the spectrum using existing bandwidths.

Bob NO6B

Re: [Repeater-Builder] 2M Vertical Dipoles

[no6b]

At 8/9/2009 05:47, you wrote:


>As frequency decreases, so does the importance of keeping the dipoles 
>exactly above one another.  This is why you can get away with mounting the 
>bays of a LB array around a smaller tower (like Rohn 25) and still have 
>very good omni-directional performance.  Positioning the bays around a 
>central supporting mast of a UHF array creates considerable pattern 
>distortion and gain is lost.

I once modeled this arrangement in NEC-Win: the resulting pattern looked 
like a warped pancake.  On-horizon gain was all over the place.

Bob NO6B

[Repeater-Builder] Antennas and feedline FS

[BJ]

We have the following surplus equipment available:

1 each Telewave ANT-150D single dipole antenna 138-172 NOS with all hardware

$175.00 each

2 each Telewave ANT-150D 4 bay dipole antenna 138-172 NOS with all hardware

$600.00 each

1 each Telewave ANT-150F2 fiberglass antenna 148-172 Demo/spare has a few 
scratches/clamp marks

$250.00 each

1 each Celwave BA1010-1 fiberglass antenna 146-164 Demo/spare in as new 
condition

$250.00 each

1 each Digital Antenna 826-VW VHF marine (designed for boat) NOS in original 
tube

$50.00 each

1 each Digital Antenna 883-CW 800/cell (designed for boat)NOS in original tube

$50.00 each

150 feet Andrew LDF4-50A 1/2" Heliax NOS

$150.00 each

200 feet Andrew FSJ4-50B 1/2" Superflex NOS

$200.00 each

All above are plus UPS shipping from 89801

Paypal or USPS MO's only

Thanks,

BJ

RE: [Repeater-Builder] Re: Narrow banding question

[N9WYS]

Agreed, Eric... but being affiliated with public safety, I also see that
some agencies (mostly municipalities with limited budgets) are waiting as
long as possible before being forced to "bite the bullet."

Mark - N9WYS

-Original Message-
From: Repeater-Builder@yahoogroups.com  On Behalf Of Eric Lemmon

All true.  However, I daresay that most of the non-convertible equipment has
already been taken out of service, long ago.  At least in my area, most
users of high-tier equipment like Spectra, TK-990, and CDM radios are
replacing them because they are getting long in the tooth- and these radios
are already narrow-band compliant.  Dual-bandwidth equipment first came on
the market more than a decade ago.

My gut feeling is that operators of large radio fleets will use the
narrow-banding deadline as a convenient time to replace the entire fleet at
once, not because of the narrow-banding requirement per se, but because they
must re-program every radio, base station, and repeater they own and do it
with minimum disruption.  When you have 2,000 radios, it can take a week or
more to reprogram the fleet.  If you use the deadline as an opportunity to
put new radios into service, you buy your 2,000 new radios a month in
advance and program and bench-test all of them on the narrow-band channels.
Just before the day you pick to make the changeover, you deliver new radios
and chargers to all users, with instructions to start using the new radios
on Monday morning.  The radio techs will ensure that the base stations
and/or repeaters are either reprogrammed or replaced just prior to that day.
If well-planned, this will work.  Obviously, users with many mobile radios
will need to allow extra time for replacing them.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com  On Behalf Of N9WYS

Albert,

This depends on the service. Public Safety and Business Radio services are
affected. Amateur Radio and GMRS are not - at this time. (IIRC)

I would certainly expect to see a glut of non-narrowband compatible
equipment enter the surplus market soon...

Mark - N9WYS

-Original Message-
From: Repeater-Builder@yahoogroups.com  On Behalf Of Albert

Yes, I realize it effects only UHF and VHF users. Maybe I was unclear with
my question.

Is is ALL VHF and UHF users? I was under the impression it was only the
upper UHF trunked systems and the like. But maybe I was confused.

Will many users have to dump their older radios and have to upgrade?

I was wondering what surplus equipment might be coming onto the market due
to the changes.

If you have seen posts from me before, I am interested in Motorola Genesis
related radio gear. I was curious if there might be a flood of it on the
market in the near future.

Thanks

Re: [Repeater-Builder] 2M Vertical Dipoles

[Kevin Custer]

As frequency decreases, so does the importance of keeping the dipoles 
exactly above one another.  This is why you can get away with mounting 
the bays of a LB array around a smaller tower (like Rohn 25) and still 
have very good omni-directional performance.  Positioning the bays 
around a central supporting mast of a UHF array creates considerable 
pattern distortion and gain is lost.  DB Products and others used a 
method of exciting two dipoles at the same elevation - the double 
dipole.  This makes the radiation center of the array the mast pipe, and 
at higher frequencies there is a big advantage to this.


Frank Rossi, N3FLR and I did testing at my Seven Springs site in the 
early 90's with a Cushcraft UHF exposed dipole array.  (Yes the ones 
with the RG-58 harness, poor connectors, and all that)  I had a UHF 
repeater hooked to it and it was side mounted on the tower with 
stand-off brackets to minimize the blocking effects of the tower.  I 
started out with the dipoles arranged one directly above another.  In 
Greensburg and Pittsburgh (about 30 and 45 miles from the site)  the 
repeater was usually full scale on Frank's S meter and he was received 
very well even on 5 watts.  My house in Friedens (about 20 miles away) 
was in the null and I received the repeater on average about S-7.  
Testing was done for several days to get a benchmark.


I then tried the antenna in omni, positioning the bays around the mast 
as Cushcraft suggested.  The result was an increase toward Friedens of 
two S units (from S-7 to S-9) and a drop towards Frank from usually full 
scale to S-5 to S-9 - a considerable loss.  It was soon learned that on 
UHF with single dipole arrays that you need to keep them one above 
another unless you can stand the considerable reduction in gain when 
going omni.  The antenna worked so much better in every other direction 
than the exact null, that I went back to the "directional" pattern and 
dealt with it. 

The Cushcraft antenna was relegated to remote base use, and still works 
some 15 years later.  It was sealed as well as could be done.  The 
repeater was connected to a top mounted Stationmaster look-alike home 
brew 23 half-waves in phase with 3 degrees of downtilt.  This antenna 
buries the S-Meter in all directions.



I know of one high profile VHF repeater in Pittsburgh that uses a dipole 
array with the dipoles faced into the tower.  It has amazing 
omni-directional range.


Kevin Custer


MCH wrote:
I'm sure someone on *this* list will be able to correct me if I'm wrong, 
but I think you can mount virtually any of the dipole type antennas on 
the tower leg as long as you're not looking for a 360 pattern. An offset 
or figure-8 pattern, though, no problem. In fact, I've done this for 
commercial users, and in some cases such as Low Band dipoles, that's the 
only way to can mount them.


You might even be able to get away with it mounting one on each leg for 
a 360 pattern (with a little more gain in one direction for a 4-bay 
antenna), but your gain would be messed up since the signal would then 
be out of phase for each element in any given direction.


Joe M.

Doug Rehman wrote:
  

I remember seeing a vertical dipole from one on the amateur antenna
manufacturers that was designed to bolt onto your mast or tower leg. I think
it might have come in a kit of 2 or 4.

I thought it was Cushcraft, but I couldn't find it. Does anyone have any
idea what antenna I thought I saw?

Thanks,
Doug
K4AC







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