[Repeater-Builder] signal group repeater power cable

[ac8dx]

anyone know where i could find a power cable for a signal group 
suitcase repeater.  this has a 50 watt amp, battery and two bendix king 
portables inside.  I need the power cable...  a 7 pin military type 
plug for the repeater unknown what would be on the other end..  
thanks... allen...

[Repeater-Builder] G.E.MVS Serice Manual

[Randy]

Does anyone know where I can find the service manual for the 40 watt 
vhf MVS on line? I cant seem to find it anywhere.
Tx's 
Randy

[Repeater-Builder] New file uploaded - Repeater Fan Controller

[George Henry]

I have uploaded the schematic for a 556-based version of the "Simple 
Repeater Fan Controller" (original 555-based version by Bob Shepard, KA9FLX) 
to the "Pix" folder in the file area on Yahoo.  I left out the LED's (you 
can all figure out where to put them if you want them) and added a diode 
across the fan/relay to protect the output transistor.

Kevin - could you add it to the website as well?  Thanks.

George, KA3HSW / WQGJ413 

Re: [Repeater-Builder] Poping or motor boating noise

[ae6la]

Yes, The short answer is yes.  The power supply ground and battery  supply 
ground were not tied together but are now.  And both the digital and  analog 
grounds are connected to the power supply ground.
 
73, Ken Sanders - AE6LA
** Check out free AOL at 
http://free.aol.com/thenewaol/index.adp.  Most comprehensive set of free 
safety and security tools, millions of free high-quality videos from across the 
web, free AOL Mail and much more.

Re: [Repeater-Builder] linking frequencies?

[no6b]

At 2/20/2007 20:05, you wrote:
>I suggest checking with your local frequency coordination group(s) for
>the bands. Linking in the 440Mhz band is generally not acceptible


... in California.  However, I understand that some other parts of the 
country have used 440-442 paired with 445-447 MHz for linking.  Maybe that 
has changed recently?

Bob NO6B

Re: [Repeater-Builder] Re: Antenna Gain Specification - dBi versus dBd

[no6b]

At 2/20/2007 21:51, you wrote:
>On 2/20/07, Ron Wright, Skywarn Coodinator <[EMAIL PROTECTED]> wrote:
>
> > When a Ringo-Ranger is advertised in Ham magazines it has 6 db gain.
> > When advertised in commerical publications/catalogs it has 4.5 db
> > gain...same antenna, same part number.
>
>Even getting 4.5dB gain out of a Ringo Resistor is impressive.  :-)
>What a hunk of... [fill in the blank].

Q.: How much gain does a Ringo Ranger have?
A.: Depends on how much of the feedline you consider part of the Ringo Ranger.

:)

Bob NO6B

RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[no6b]

At 2/20/2007 18:08, you wrote:
>Ken,
>
>I, too, used a Greenlee hole punch before I discovered the Ripley HSK-19
>Antenna Hole Saw.  The description in the catalog states:  "Ripley hole saw
>for installing permanent mount antennas.  Makes 3/4" hole and limits depth
>to 1/8"..."  It is sold by Tessco as catalog number 14023.  It's a lot less
>cumbersome than the hole punch method, but the user still needs to consider
>where the dome light and/or roof support ribs are located, before drilling.
>Funny how some people don't check these details!

I'm by no means an expert in mobile installs.  In fact, I'm quite a novice 
in that area & probably always will be.  However, I did discover one simple 
trick for locating the correct spot to drill the mounting hole:

Remove the dome light & locate the spot to drill from the bottom, through 
the dome light area so you know where you can put the hole & have room for 
the coax.  Then center-punch the spot from the bottom, making a raised 
dimple in the rooftop.  Then take the punch to the rooftop, center it on 
the dimple & punch again, inverting the dimple so you can then drill your 
mounting hole from the top.

Also be careful to use either a quality hole saw, or one that's undersized 
by 1/16 in.  The first 3/4 in. saw I used had a bit of wobble in it & 
almost made the hole too big for the rooftop NMO mount.  Boy would that 
have been embarrassing if the hole really had been too big & the mount 
slipped through!

Bob NO6B

Re: [Repeater-Builder] Whiskers

[no6b]

At 2/20/2007 16:20, you wrote:
>Well, I've been playing with GE MVP's, Exec II's and Mastr II's for years
>and never had a casting develop whiskers... until now. This was a VHF high
>band MVP and when I took it apart, there was one whisker that had to go an
>inch long. That particular helical section was completely "dead" to tuning.
>Many more smaller ones in there as well.
>
>I'm not sure if there's a good solution short of another casting, but I
>cleaned them out with a brush and am now running the casting and covers
>through the dishwasher (before my wife gets home!). Hopefully this will keep
>things at bay for several years.
>
>Chuck
>WB2EDV

Anyone have an idea as to how long it takes for them to grow?  When I have 
one, I just break it off by running the helical adjustment through its 
entire range.  Never had one come back.

Bob NO6B

Re: [Repeater-Builder] Re: Antenna Gain Specification - dBi versus dBd

[no6b]

At 2/20/2007 05:39, you wrote:

>Could never understand why a Diamond long 18 ft dual band antenna has
>about 8 dbd on VHF/11 dbd on UHF when a commerical antenna like the
>Super Station Master or DB224 has 6 db.  Think the commerical people
>know why, not, hi.

The Diamond specs are actually dBi, not dBd.  If they claim dBd, it's false 
advertising.  Someday if I find one torn apart I'll build a model of it in 
NEC-Win to prove it.



>QST for a long time refused to print gain specs in the ads for they
>knew most was smoke.

Yes, but not publishing gain specs for antennas is sort of like not 
publishing power ratings for amplifiers or amperage ratings for 12 V power 
supplies.

Bob NO6B

Re: [Repeater-Builder] Whiskers

[Nate Duehr]

On 2/20/07, Chuck Kelsey <[EMAIL PROTECTED]> wrote:
> Well, I've been playing with GE MVP's, Exec II's and Mastr II's for years
> and never had a casting develop whiskers... until now. This was a VHF high
> band MVP and when I took it apart, there was one whisker that had to go an
> inch long. That particular helical section was completely "dead" to tuning.
> Many more smaller ones in there as well.
>
> I'm not sure if there's a good solution short of another casting, but I
> cleaned them out with a brush and am now running the casting and covers
> through the dishwasher (before my wife gets home!). Hopefully this will keep
> things at bay for several years.
>
> Chuck
> WB2EDV

Some people have reported success with taking the casting apart and
carefully and lightly spraying the inside with clear spray paint --
something inert that won't affect the RF but will permanently seal it
and keep the whiskers from growing from the casting to the coils.

Nate WY0X

Re: [Repeater-Builder] Re: Antenna Gain Specification - dBi versus dBd

[Nate Duehr]

On 2/20/07, Ron Wright, Skywarn Coodinator <[EMAIL PROTECTED]> wrote:

> When a Ringo-Ranger is advertised in Ham magazines it has 6 db gain.
> When advertised in commerical publications/catalogs it has 4.5 db
> gain...same antenna, same part number.

Even getting 4.5dB gain out of a Ringo Resistor is impressive.  :-)
What a hunk of... [fill in the blank].

> QST for a long time refused to print gain specs in the ads for they
> knew most was smoke.

Then they realized who was *really* paying the bills?  Ha!  :-)

Nate WY0X

Re: [Repeater-Builder] Antenna dBd Vs dBd

[Nate Duehr]

On 2/20/07, Jim Cicirello <[EMAIL PROTECTED]> wrote:

> It is important to note that antenna gain is different than amplifier
> gain. Antennas do not have a power source that allows the antenna to
> create additional energy to boost the signal. An antenna is similar to
> a reflective lens in principle - it takes the energy available from
> the source and focuses it over a wider or narrower area.

Antenna gain finally "clicked" for me one day when someone used the
example of one of the original non-LED small MagLite flashlights.

Stand about 20 feet from a wall in a semi-dark room...

Take the lens off... the MagLite looks like a little candle... light
radiating in all directions.
Note the amount of light on the wall at a particular spot.  This is
your isotropic radiator... well kinda... close enough for this demo,
anyway.  A "point" of light".

Screw the lens back on and aim the flashlight at the wall.  Turn the
focus (more gain) to make the spot on the wall smaller and smaller...
note how the spot gets "brighter".

(Well the reflected light off the wall back to your eyes is what
you're really seeing... but anyway, ignore that part...)

The flashlight is "transmitting" the same amount of light throughout
this entire exercise, but as you focus the lens on the spot you want
the light to illuminate you send more light that direction.

Same thing works the other direction (careful not to hurt eyes, here
if you actually try any of this stuff!... of course).  You can have
someone look at our little tiny MagLite across a mile or more with a
telescope -- a REALLY "high gain" light antenna (lens)... so to speak.

If you can make the mental leap here and pretend these are all your
favorite high and low gain antennas (for whatever band...) you start
to get the idea...

In your imagination, it helps show why the guys with big beams can
always still hear the pip-squeaks with bad antennas but they can't
hear off to the side -- 'cause they're looking with a TELESCOPE for
them! -- and how the gain of a particular antenna squeezes its pattern
out to the horizon (we hope)... and not the sky...

Just imagine your antenna radiates light (not RF... but hey, it's
still the all part of the spectrum) and where all that "light" is
going to go, and what little lights you'll be able to see "out that
direction" if you're using highly directional antennas... makes for a
decent (but not 100% perfect) mental model...

I always thought it'd be neat (if I were a good graphics design coder,
which I most definitely am NOT) to build a path prediction software
package that would show each transmitter as a 3-dimensional light
source.  3-dimensional instead of 2-dimensional like most path
prediction software is now.

But talk about a nightmare to code.  Sure would look nifty, though.

Especially if you could simulate real system activity in a linked
system and "fly around the radio system" in 3D, like Google Earth...
see where all that RF is really going... add topographic data... etc
etc etc.

I suppose the big boys (commercial or government) who can afford to
pay someone to write such code, probably have toys like this,
somewhere...

Nate WY0X

[Repeater-Builder] FS: Complete HP Network Analyzer

[drd_007]

Dear Colleagues,

  I've laid out the big bucks and purchased an HP 8753C network 
analyzer so my previous and trusty HP 8505A system is now offered for 
sale.  Using a network analyzer provides the fastest and most 
accurate means of tuning duplexers.  Here are the details. 

   It's completely functional (has served as my own personal unit) 
and it's one of the cleanest ones I've ever seen.  It comes as a 
complete system. All cables, manuals, overlays and accessories are 
included. Anyone buying this unit will take it home, apply power and 
have a fully functioning unit.

  The HP 8505A system covers 500kHz to 1300MHz.  It's a vector 
analyzer.  There is a complete set of overlays so Smith Chart, log 
freq, etc. points can be read directly.  All 4 S-Parameters can be 
measured without disconnecting the DUT since the S-Parameter test set 
is included.  The trace can be smoothed and averaged with the Storage 
Normalizer Set.

   The system comes complete in 4 stackable and locking units as such:

HP 8501A Storage Normalizer
HP 8505A Network Analyzer
 Source Converter
HP 8503A S-Parameter Test Set

All operating and service manuals are included in print form as 
well as various application notes and getting started guides.

   For anyone able to pick up the unit here, there will be a special 
surprise.  I will include a spare unit (Storage Normalizer, Network 
Analyzer and Source Converter only less the S-Parameter test set) for 
free for sparing me the trouble of packing and shipping.

   This is the same analyzer seen in the photo on page 9-61 of 
ON4UN's, "Low-Band DX-ing," 4th edition.  In addition to antenna 
matching, it makes tuning duplexers a breeze.

   Please contact me off list if interested.

Thanks, 

Mike DiGirolamo, W4XN
Charlottesville, VA
[EMAIL PROTECTED]
 
 

Re: [Repeater-Builder] linking frequencies?

[Gary]

I suggest checking with your local frequency coordination group(s) for
the bands. Linking in the 440Mhz band is generally not acceptible
however the 420-430Mhz portion of the amateur 70cm band is used for
linking in some regions.
Gary

let_cyber wrote:

> Is 900 Mhz still useable for repeater linking, or is it so full of
> garbage that there would be problems? How about 440 Mhz?
>
> Thanks, Al KB2AYU
>
>
> Yahoo! Groups Links
>
>
>

[Repeater-Builder] Re: Poping noise

[Al Wolfe]

Yes, the Vatican does have a lot of influence around the world. 

Sorry, couldn't resist.

73,
Al, K9SI

[Repeater-Builder] linking frequencies?

[let_cyber]

Is 900 Mhz still useable for repeater linking, or is it so full of 
garbage that there would be problems? How about 440 Mhz?

Thanks, Al KB2AYU

[Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Maxwell D Pratt]

--- In Repeater-Builder@yahoogroups.com, Ken Arck <[EMAIL PROTECTED]> wrote:
>
> At 07:29 AM 2/20/2007, you wrote:
> 
> I have friends That think drilling a hole in a car or truck new or 
even a used one is a sin . I try not to but if necessary to get 
Antenna on ill go for the drill and Greenlee punch and I have a good 
one "Hydraulic" it will punch S/S up to 3" .

DaleN8SAC

> 
> >Ah, the gold old days, when men armed with a drill and Greenlee 
punch
> >thought nothing of putting holes in their roofs, fearing not the 
Wrath of
> >Wife.
Ken
> 
--
> President and CTO - Arcom Communications
> Makers of the world famous RC210 Repeater Controller and 
accessories.
> http://www.arcomcontrollers.com/
> Authorized Dealers for Kenwood and Telewave and
> we offer complete repeater packages!
> AH6LE/R - IRLP Node 3000
> http://www.irlp.net
>

RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Eric Lemmon]

Ken,

I, too, used a Greenlee hole punch before I discovered the Ripley HSK-19
Antenna Hole Saw.  The description in the catalog states:  "Ripley hole saw
for installing permanent mount antennas.  Makes 3/4" hole and limits depth
to 1/8"..."  It is sold by Tessco as catalog number 14023.  It's a lot less
cumbersome than the hole punch method, but the user still needs to consider
where the dome light and/or roof support ribs are located, before drilling.
Funny how some people don't check these details!

My disclaimer of financial interest in Ripley or Tessco applies- I'm just a
satisfied customer.

73, Eric Lemmon WB6FLY


-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Ken Arck
Sent: Tuesday, February 20, 2007 7:42 AM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial
and amateur

At 07:29 AM 2/20/2007, you wrote:

>Ah, the good old days, when men armed with a drill and Greenlee punch
>thought nothing of putting holes in their roofs, fearing not the Wrath of
>Wife.

<---When I bought my new Mustang last year, within 24 hours of 
bringing it home, I installed a genuine NMO mount in the trunk lid. 
Of course, I've always sworn by using Greenlee punches for the hole 
too (none of those stepped drill bits for me!)

My wife didn't even question me, other than "what took you so long"?

Ken

Re: [Repeater-Builder] Re: Antenna gain specs

[Steven Samuel Bosshard \(NU5D\)]

I belive the double dipole (304) was supposed to have a more omni-directional 
pattern (the books show a 'normalized' pattern) - I will have to dig out some 
old DB Products catalogs, or call Lloyd Alcorn in Waco (he designed the 224 for 
DB before he and Kit Parsons and Larry Bush started Wacom Products) and get the 
info.  Steve

[Repeater-Builder] Whiskers

[Chuck Kelsey]

Well, I've been playing with GE MVP's, Exec II's and Mastr II's for years 
and never had a casting develop whiskers... until now. This was a VHF high 
band MVP and when I took it apart, there was one whisker that had to go an 
inch long. That particular helical section was completely "dead" to tuning. 
Many more smaller ones in there as well.

I'm not sure if there's a good solution short of another casting, but I 
cleaned them out with a brush and am now running the casting and covers 
through the dishwasher (before my wife gets home!). Hopefully this will keep 
things at bay for several years.

Chuck
WB2EDV 

RE: [Repeater-Builder] Re: Antenna gain specs

[Gary Schafer]

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Laryn Lohman
> Sent: Tuesday, February 20, 2007 5:59 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: Antenna gain specs
> 
> --- In Repeater-Builder@yahoogroups.com, "Steven Samuel Bosshard
> \(NU5D\)" <[EMAIL PROTECTED]> wrote:
> >
> > What I don't understand is how at times the DB224 is rated at 4.5
> dBd, then 6 dBd,
> 
> H that's a new one.  Where/when and what frequency range have
> you seen the DB224 rated at 4.5dbd?
> 
> 
> > and the DB304 (twice as much aluminum) rated at 6.1 dBd.  over a
> span of 30 years...de nu5d
> 
> Omnidirectional gain is achieved by vertically stacking more "levels",
> if you will.  Doing what they've done with the DB304 does not add more
> levels.  So no more gain.
> 
> To be honest, I'm not sure what the reason is for the double dipole
> arrangement.  I suspect it electrically makes the mast 
> since each pair is symmetrical with the mast.  Someone else I'm sure
> has a better explanation of this design.
> 
> Laryn K8TVZ
> 

When you look at the antenna patterns in the catalogs they look like nice
smooth circles for the gain pattern. This is far from realistic as most
antennas will have many many peaks and nulls in the pattern. What the
diagram in the catalogs try to show is an average gain pattern.
The addition of more elements on the same level in antennas such as the
DB304 will "fill" in more of those peaks and nulls to make a better more
consistent pattern. They can also be used to make the antenna more broad
band.


73
Gary  K4FMX

Re: [Repeater-Builder] Re: Antenna gain specs

[w5zit]

But don't mount it upside down.  The base is not waterproof when 
inverted  -

I learned that the hard way!

73 - Jim  W5ZIT

-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Tue, 20 Feb 2007 3:19 PM
Subject: [Repeater-Builder] Re: Antenna gain specs


>
> When it comes to gain, the Diamond probably really has 8.3 dBi.

That's probably true Bob. And the grapes to grapes comparison would
suggest that a DB224 also has ~8.3dbi of gain.

The real
> difference between the two antennas is pattern shape (DB224 has a
"cleaner"
> pattern; the dual-band antennas have deeper nulls below the horizon),

Can't argue there.

and
> of course the mechanical ruggedness of the DB224.
>
> Bob NO6B
>

For sure. Try top mounting one of the long, slender fiberglass sticks
and you'll probably be replacing it sooner than you'd like. Side
mounted and supported with at least one stay somewhere above halfway,
it'll last a long time.

Laryn K8TVZ







Check Out the new free AIM(R) Mail -- 2 GB of storage and 
industry-leading spam and email virus protection.
=0

[Repeater-Builder] Re: Antenna gain specs

[Laryn Lohman]

--- In Repeater-Builder@yahoogroups.com, "Steven Samuel Bosshard
\(NU5D\)" <[EMAIL PROTECTED]> wrote:
>
> What I don't understand is how at times the DB224 is rated at 4.5
dBd, then 6 dBd,

H that's a new one.  Where/when and what frequency range have
you seen the DB224 rated at 4.5dbd?


> and the DB304 (twice as much aluminum) rated at 6.1 dBd.  over a
span of 30 years...de nu5d

Omnidirectional gain is achieved by vertically stacking more "levels",
if you will.  Doing what they've done with the DB304 does not add more
levels.  So no more gain.  

To be honest, I'm not sure what the reason is for the double dipole
arrangement.  I suspect it electrically makes the mast 
since each pair is symmetrical with the mast.  Someone else I'm sure
has a better explanation of this design.

Laryn K8TVZ

Re: [Repeater-Builder] Poping Noise

[Adam Vazquez]

Check your deviation, maybe you are exceeding the bandwidth of your
receiver.

Adam Kb2jpd

On 2/20/07, Shorty Stouffer <[EMAIL PROTECTED]> wrote:


Ken Sanders - AE6LA wrote...
We just replaced the 1980s era SC-1 controller with an Arcom RC210 and
have a
poping noise when repeating but not during the voice announcements. Any
suggestions for a cure will be appreciated.

You might also look at the audio level coming into the controller from the
RX.  It may be too hot.  Should be about 2 volts p-p at fiull system
deviation (5 kHz).


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

Re: [Repeater-Builder] Poping or motor boating noise

[Jeff Otterson]

Is the speaker connected to the MASTR II?  If you disconnected the speaker, 
the AF amp can oscillate, which could make this noise...

Jeff

At 05:33 PM 2/20/2007, you wrote:

>There could be a number of reasons. You are going to have to be a
>little more specific as Poping a really vague term. If possible try
>recording it and post it as a .WAV or .MP3.
>
>This could be anything from a loose wire to desence caused by the
>oscillators in the controller.
>
>My research says:
>
>"I've seen that crap before"
>
>+10V mic bias coming from the exciter down the audio path into the
>controller and not playing nice with the half VCC biased amplifiers.
>This can also be a problem in the long run as a +10 volt biased line
>on the output will charge the AC coupling capcitors backwards which
>are between 6 and 7 volts on their positive side and cause them to
>fail.
>
>I've even had the capacitors stop passing audio, wait for me to get to
>the site, open the equipement, and blow up, right in my face... Mike
>Rowe would be proud... Anyway, electrolytic or any other polarized
>capacitors do not belong in an AC path where DC bias can occur.
>
>If this is your problem there are a number of solutions. One would be
>to put a non-polar capacitor in series with your TX audio path or
>replace the polarized capcitors in the controller with non-polar
>ceramics. I personally would recommend eliminating the bias supply
>resistor from the MASTR-II exciter, I think it was a 620 or 680 ohm
>resistor.
>
>But this may not be your problem...
>
>On 2/20/07, Ken Sanders <[EMAIL PROTECTED]> wrote:
> > Hi All,
> >
> > I'm pretty inexperienced but find myself in charge of a nice repeater
> > operation, 145.170 - N6FRG in Angels Camp, CA. This is a GE Mastr II
> > mobil unit that has been in service for many, many years. We just
> > replaced the 1980s era SC-1 controller with an Arcom RC210 and have a
> > poping noise when repeating but not during the voice announcements. Any
> > suggestions for a cure will be appreciated.
> >
> > 73, Ken Sanders - AE6LA
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
>

Re: [Repeater-Builder] Poping or motor boating noise

[DCFluX]

There could be a number of reasons. You are going to have to be a
little more specific as Poping a really vague term. If possible try
recording it and post it as a .WAV or .MP3.

This could be anything from a loose wire to desence caused by the
oscillators in the controller.

My research says:

"I've seen that crap before"

+10V mic bias coming from the exciter down the audio path into the
controller and not playing nice with the half VCC biased amplifiers.
This can also be a problem in the long run as a +10 volt biased line
on the output will charge the AC coupling capcitors backwards which
are between 6 and 7 volts on their positive side and cause them to
fail.

I've even had the capacitors stop passing audio, wait for me to get to
the site, open the equipement, and blow up, right in my face... Mike
Rowe would be proud... Anyway, electrolytic or any other polarized
capacitors do not belong in an AC path where DC bias can occur.

If this is your problem there are a number of solutions. One would be
to put a non-polar capacitor in series with your TX audio path or
replace the polarized capcitors in the controller with non-polar
ceramics. I personally would recommend eliminating the bias supply
resistor from the MASTR-II exciter, I think it was a 620 or 680 ohm
resistor.

But this may not be your problem...


On 2/20/07, Ken Sanders <[EMAIL PROTECTED]> wrote:
> Hi All,
>
> I'm pretty inexperienced but find myself in charge of a nice repeater
> operation, 145.170 - N6FRG in Angels Camp, CA.  This is a GE Mastr II
> mobil unit that has been in service for many, many years.  We just
> replaced the 1980s era SC-1 controller with an Arcom RC210 and have a
> poping noise when repeating but not during the voice announcements. Any
> suggestions for a cure will be appreciated.
>
> 73, Ken Sanders - AE6LA
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>

Re: [Repeater-Builder] Re: Antenna gain specs

[Steven Samuel Bosshard \(NU5D\)]

What I don't understand is how at times the DB224 is rated at 4.5 dBd, then 6 
dBd, and the DB304 (twice as much aluminum) rated at 6.1 dBd.  over a span of 
30 years...de nu5d

[Repeater-Builder] Re: Antenna gain specs

[Laryn Lohman]

> 
> When it comes to gain, the Diamond probably really has 8.3 dBi. 

That's probably true Bob.  And the grapes to grapes comparison would
suggest that a DB224 also has ~8.3dbi of gain.  

 The real 
> difference between the two antennas is pattern shape (DB224 has a
"cleaner" 
> pattern; the dual-band antennas have deeper nulls below the horizon),

Can't argue there.

 and 
> of course the mechanical ruggedness of the DB224.
> 
> Bob NO6B
>

For sure.  Try top mounting one of the long, slender fiberglass sticks
and you'll probably be replacing it sooner than you'd like.  Side
mounted and supported with at least one stay somewhere above halfway,
it'll last a long time. 

Laryn K8TVZ

Re: [Repeater-Builder] Poping or motor boating noise

[Ken Arck]

At 12:56 PM 2/20/2007, you wrote:

>Hi All,
>
>I'm pretty inexperienced but find myself in charge of a nice repeater
>operation, 145.170 - N6FRG in Angels Camp, CA. This is a GE Mastr II
>mobil unit that has been in service for many, many years. We just
>replaced the 1980s era SC-1 controller with an Arcom RC210 and have a
>poping noise when repeating but not during the voice announcements. Any
>suggestions for a cure will be appreciated.

<---Obviously first question - do you have both the analog and 
digital ground connections made at the RC210's power connector?

Ken
--
President and CTO - Arcom Communications
Makers of the world famous RC210 Repeater Controller and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net

Re: [Repeater-Builder] Re: Antenna gain specs

[Bob Dengler]

At 2/20/2007 07:11 AM, you wrote:
>Paul Holm wrote:
> > Reading the replies that mentioned gain specs, I can't help but think 
> of our
> > last ham club meeting.  An older member persuaded the club to replace the
> > VHF repeater antenna with a Diamond X500HNA rather than a DB-224 
> because the
> > Diamond "has 8.3 dB gain".
>
>And even worse is that the rest of the club was stupid enough to listen...

When it comes to gain, the Diamond probably really has 8.3 dBi.  The real 
difference between the two antennas is pattern shape (DB224 has a "cleaner" 
pattern; the dual-band antennas have deeper nulls below the horizon), and 
of course the mechanical ruggedness of the DB224.

Bob NO6B

[Repeater-Builder] Poping or motor boating noise

[Ken Sanders]

Hi All,

I'm pretty inexperienced but find myself in charge of a nice repeater 
operation, 145.170 - N6FRG in Angels Camp, CA.  This is a GE Mastr II 
mobil unit that has been in service for many, many years.  We just 
replaced the 1980s era SC-1 controller with an Arcom RC210 and have a 
poping noise when repeating but not during the voice announcements. Any 
suggestions for a cure will be appreciated.

73, Ken Sanders - AE6LA   

[Repeater-Builder] Duplexer ID

[George Henry]

Can anyone tell me which Celwave model a Motorola TDN7407A is, or provide the 
specs on it?



George, KA3HSW / WQGJ413

[Repeater-Builder] Re: Antennas that work both in commercial and amateur (war stories)

[skipp025]

A number of years ago... an installer I knew drilled a cell phone 
mount into the transmission hump of a Jag... caught the Jag's wire 
harness and shorted/burned the entire car out when he hit the key. 

T'was a $4,000 + cost dealer fix...  

cheers, 
skipp 



> "Paul Finch" <[EMAIL PROTECTED]> wrote:
> Hello,
> 
> Anyone remember Ed Juge?  I worked for him back when he had his 
> electronics shop on the South Freeway in Fort Worth.  His wife 
> got a new car, a little Porsche 911 and she wanted a Ham radio 
> installed so she could use the local .94/10-4 repeater, Ed knew 
> better than to try and install it on the roof. As a joke, he took 
> a Larson gain antenna and set it on top of the car's roof
> while calling her to come see his handywork.  Jo walked in, you 
> could hear the scream all over the building!  The customers were 
> wondering what was happening!
> 
> Sorry for the off-topic story but seemed appropriate!
> Paul
> 

RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Paul Finch]

Hello,

Anyone remember Ed Juge?  I worked for him back when he had his electronics
shop on the South Freeway in Fort Worth.  His wife got a new car, a little
Porsche 911 and she wanted a Ham radio installed so she could use the local
.94/10-4 repeater, Ed knew better than to try and install it on the roof.
As a joke, he took a Larson gain antenna and set it on top of the car's roof
while calling her to come see his handywork.  Jo walked in, you could hear
the scream all over the building!  The customers were wondering what was
happening!

Sorry for the off-topic story but seemed appropriate!

Paul



-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Ken Arck
Sent: Tuesday, February 20, 2007 9:42 AM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial
and amateur

At 07:29 AM 2/20/2007, you wrote:



>Ah, the gold old days, when men armed with a drill and Greenlee punch 
>thought nothing of putting holes in their roofs, fearing not the Wrath 
>of Wife.

<---When I bought my new Mustang last year, within 24 hours of bringing it
home, I installed a genuine NMO mount in the trunk lid. 
Of course, I've always sworn by using Greenlee punches for the hole too
(none of those stepped drill bits for me!)

My wife didn't even question me, other than "what took you so long"?

Ken

--
President and CTO - Arcom Communications Makers of the world famous RC210
Repeater Controller and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and we offer complete repeater
packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net





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

[Paul Finch]

Jordan,

Are you duplexing the radio to make a remote receiver with a UHF link,
something like that?  Are you sure you have made all the mods?  How close is
the transmit to the receive frequency if duplexing.  

You do need to make that mod, if it's the UHF version you need to shield the
bottom of the driver or predriver transistor, can't remember for sure but
think it's the driver.  I build mine out of brass shim-stock that's about
1/64 inch thick, there are several points around the transistor to fold over
the corners to solder to ground.  Place a piece of fish paper, the old
plastic coated hard paper between the shield and the foil so it does not
short out.  Without the shield there is a slight amount of desense you have
to contend with, with the shield it goes away and you can turn the
transmitter up all the way if you want to with no problems.

With that said, I have not tried to duplex a VHF PPL 6050.  I need to try
that!  

Paul
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of twoway_tech
Sent: Monday, February 19, 2007 9:37 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Johnson PPL 6060 manual needed

Well, Speaking of EFJ PPLs, has anyone accually performed the repeater  mods
that are descibed on the repeater builder page? I have done one radio, but I
am getting RF into the receiver. Jim Sharp (the author) mentions putting a
shield around Q1, but the transistors are not labeled that way. I don't
really see any EASY way to install any shield that would do much good due to
the trace layout on the board.
By-the-way, I tried to contact Jim Sharp and had no luck. Anyway, I am
trying to use one of these radios for a remote receiver on 448.325RX and
433.050TX (radio tuned up fine). When the radio keys up, I get a squealing
noise. Even when there is just squelch noise and no RX signal. It sounds
like RF to me. If anyone has hints of ideas, let me know. Also I want to
thanks Eric for the manual posting!

-Jordan


--- In Repeater-Builder@yahoogroups.com, "Paul Finch" <[EMAIL PROTECTED]>
wrote:
>
> George,
> 
> The PPL series radios are very good as well as being easy to work
on.  You
> can almost trace the signal path without a schematic even without 
> experience, I do but I worked on them when they first came out in
the late
> 70's early 80's.  You can do a lot with these little radios.
> 
> Paul
> 
> 
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com 
> [mailto:[EMAIL PROTECTED] On Behalf Of Eric Lemmon
> Sent: Saturday, February 17, 2007 5:10 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: RE: [Repeater-Builder] Johnson PPL 6060 manual needed
> 
> George,
> 
> By an amazing coincidence, I am just now scanning a Johnson PPL-6060
Service
> Manual into PDF for posting on the RBTIP.  I can send you the same
file this
> evening.  Some PPL-6060 info is already available here:
> 
> 
> 
> 73, Eric Lemmon WB6FLY
> 
> 
>  
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com 
> [mailto:[EMAIL PROTECTED] On Behalf Of George Henry
> Sent: Saturday, February 17, 2007 2:08 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Johnson PPL 6060 manual needed
> 
> Just picked up a bunch of these on eBay, 2 of which supposedly need 
> repair Anybody got a manual I can copy & return, or buy outright?
> 
> George, KA3HSW / WQGJ413
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
> 
> 
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> 2:25 PM
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> 
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RE: [Repeater-Builder] Re: Johnson PPL 6060 manual needed

[Paul Finch]

Hello,

I did those Mods before there was a Repeater Builder website, like I said in
the other email they are great little radios and make great inexpensive low
power repeaters, if you call 15 to 20 watts low power!

Paul

 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of twoway_tech
Sent: Tuesday, February 20, 2007 9:13 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Johnson PPL 6060 manual needed

Well, keep me posted on your findings with these things... I have a few
laying around that I already have Xtals for and want to get going.
I'll let you know if I find anything new.


-Jordan 

--- In Repeater-Builder@yahoogroups.com, "ka3hsw" <[EMAIL PROTECTED]> wrote:
>
> --- In Repeater-Builder@yahoogroups.com, "twoway_tech" 
> wrote:
> >
> > Well, Speaking of EFJ PPLs, has anyone accually performed the 
> > repeater  mods that are descibed on the repeater builder page? I 
> > have done one radio, but I am getting RF into the receiver. Jim 
> > Sharp (the author) mentions putting a shield around Q1, but the 
> > transistors are not labeled that way. I don't really see any EASY 
> > way to install any shield that would do much good due to the trace
layout on the board.
> 
> [snip]
> 
> Haven't done one yet, but have been studying the docs and, according 
> to the block diagram and schematic, the first RF amp is actually Q201.
> There is a picture of where to solder the shield in the "updated-ppl- 
> board.doc" file, linked from the conversion page.  It goes on the foil 
> side of the board, almost dead-center side-to-side, about 1/4 of the 
> way forward from the rear edge.
> 
> George, KA3HSW / WQGJ413
>






 
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RE: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd

[Gary Schafer]

Hi Allan,

 

Here is a way to look at it that may help:

 

A 6 db increase in voltage doubles the voltage.

A 3 db increase in power doubles the power.

A 6 db increase in power quadruples power (4x).  (An easy way to do that
is.. 2x power = 3 db. 2x power again = 6 db).

 

Now if we do it by ohms law, let's say we have 10 volts to start with across
50 ohms. E squared /R = P.

So 10x10=100 volts divided by 50 ohms = 2 watts.

 

If we increase the 10 VOLTS by 6 db that gives us 20 volts. To find the
power now across our 50 ohms we have: 20x20=400 volts divided by 50 ohms = 8
watts.

 

If we go back and increase our POWER by 6 db from our 2 watts that gives us
8 watts. We end up with the same power increase either way.

 

So it doesn't matter if we are using power or voltage as a reference, the
amount of energy (signal strength) works out the same way. The only thing we
have to watch out for is to not mix the two.

 

73

Gary  K4FMX

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of allan crites
Sent: Tuesday, February 20, 2007 11:40 AM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd

 

Now that dBi Vs dBd seems to have been settled, perhaps there is someone who
cares to explain if antenna manufacturers express their antenna gain with
voltage dB's or in power dB's. There is a difference.

 

Allan Crites

WA9ZZU

Gary Schafer <[EMAIL PROTECTED]> wrote:



> -Original Message-
> From: Repeater-Builder@ 
yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED]  .com] On Behalf Of
Eric Lemmon
> Sent: Tuesday, February 20, 2007 1:21 AM
> To: Repeater-Builder@ 
yahoogroups.com
> Subject: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd
> 
> The Telecommunications Industry Association, an international organization
> which develops standards to which nearly all countries of the world have
> subscribed, has already taken steps to correct the misleading practice of
> indiscriminately using dBi where dBd is appropriate.
> 
> According to TIA-329-C, published in 2003, base station antenna gain for
> less than 1 GHz shall expressed in dBd using a dipole antenna as a
> reference. Antenna gain for 1 GHz and above shall be expressed in dBi
> using
> a theoretical isotropic radiator as a reference. There are no exceptions.
> So, why are some manufacturers still using dBi for their 2m and 70cm
> antennas? 

Unfortunately dBd is not a cure all. Dbi is the true way to compare antennas
however not always the most convenient. One problem with dBi is that it
assumes free space. The dBd also assumes free space but is impossible to
test in true free space. When you get into the lower frequencies it becomes
more of a problem.

>There are probably several answers to that question, such as:
> 
> 1. Perhaps most antenna buyers don't know the difference between dBi and
> dBd.
> 2. Perhaps most antenna buyers believe whatever the ad copy says.
> 3. Perhaps the company owner is an old-school believer that dBi is the
> only
> "true" gain unit.
> 4. Perhaps the antenna designer knows about TIA-329-C, but chooses to
> ignore it.
> 
> It should be obvious that microwaves, which begin around 1 GHz, behave a
> lot
> like light and can be focused with a parabolic reflector. Short radio
> waves
> are easy to visualize as being generated by a point source, very much like
> a
> bulb in a parabolic flashlight reflector. Such point sources can be
> easily
> expressed as isotropic radiators, and the leap to dBi is logical. 

There is nothing unique about 1GHz over the lower frequencies being like
light waves.

> The
> wavelength of lower-frequency waves in the VHF and UHF spectra are not
> point
> sources, and it is illogical to expend any effort "converting" from one
> reference to the other. 

Neither are sources above 1GHz "point sources" any more than a 1 MHz signal
is. It is all a matter of scale. 

>As several others have pointed out, there is
> about
> 2.14 dB difference between the absolute gain expressed as dBi and that
> expressed as dBd.

This is only in free space.

> 
> Unfortunately, there will always be some "fringe group" that will argue
> until the end of time that dBi is the Nirvana of antenna gain expression.
> I
> doubt that the decision by the TIA to limit dBi as an antenna gain unit to
> 1
> GHz and above will change their beliefs. 

Antenna theory sometimes becomes like religion for many.

>Getting the antenna
> manufacturers
> to properly report the gain of their products is quite another thing. 

It is a good thing to have some standard that figures are reported by to
lower the confusion factor.

> As
> previous posters have mentioned, some popular antennas are junk that has
> never been properly tested on an antenna range, resulting in ridiculously
> inflated and undocumented

RE: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd

[Ken Arck]

At 08:40 AM 2/20/2007, you wrote:

>Now that dBi Vs dBd seems to have been settled, perhaps there is 
>someone who cares to explain if antenna manufacturers express their 
>antenna gain with voltage dB's or in power dB's. There is a difference.

<---Not really. Decibels describe performance independently of 
operating power or voltage. Me thinks you're confusing dB with dBm perhaps?

Ken

--
President and CTO - Arcom Communications
Makers of the world famous RC210 Repeater Controller and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net

RE: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd

[allan crites]

Now that dBi Vs dBd seems to have been settled, perhaps there is someone who 
cares to explain if antenna manufacturers express their antenna gain with 
voltage dB's or in power dB's. There is a difference.
   
  Allan Crites
  WA9ZZU

Gary Schafer <[EMAIL PROTECTED]> wrote:
  

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Eric Lemmon
> Sent: Tuesday, February 20, 2007 1:21 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd
> 
> The Telecommunications Industry Association, an international organization
> which develops standards to which nearly all countries of the world have
> subscribed, has already taken steps to correct the misleading practice of
> indiscriminately using dBi where dBd is appropriate.
> 
> According to TIA-329-C, published in 2003, base station antenna gain for
> less than 1 GHz shall expressed in dBd using a dipole antenna as a
> reference. Antenna gain for 1 GHz and above shall be expressed in dBi
> using
> a theoretical isotropic radiator as a reference. There are no exceptions.
> So, why are some manufacturers still using dBi for their 2m and 70cm
> antennas? 

Unfortunately dBd is not a cure all. Dbi is the true way to compare antennas
however not always the most convenient. One problem with dBi is that it
assumes free space. The dBd also assumes free space but is impossible to
test in true free space. When you get into the lower frequencies it becomes
more of a problem.

>There are probably several answers to that question, such as:
> 
> 1. Perhaps most antenna buyers don't know the difference between dBi and
> dBd.
> 2. Perhaps most antenna buyers believe whatever the ad copy says.
> 3. Perhaps the company owner is an old-school believer that dBi is the
> only
> "true" gain unit.
> 4. Perhaps the antenna designer knows about TIA-329-C, but chooses to
> ignore it.
> 
> It should be obvious that microwaves, which begin around 1 GHz, behave a
> lot
> like light and can be focused with a parabolic reflector. Short radio
> waves
> are easy to visualize as being generated by a point source, very much like
> a
> bulb in a parabolic flashlight reflector. Such point sources can be
> easily
> expressed as isotropic radiators, and the leap to dBi is logical. 

There is nothing unique about 1GHz over the lower frequencies being like
light waves.

> The
> wavelength of lower-frequency waves in the VHF and UHF spectra are not
> point
> sources, and it is illogical to expend any effort "converting" from one
> reference to the other. 

Neither are sources above 1GHz "point sources" any more than a 1 MHz signal
is. It is all a matter of scale. 

>As several others have pointed out, there is
> about
> 2.14 dB difference between the absolute gain expressed as dBi and that
> expressed as dBd.

This is only in free space.

> 
> Unfortunately, there will always be some "fringe group" that will argue
> until the end of time that dBi is the Nirvana of antenna gain expression.
> I
> doubt that the decision by the TIA to limit dBi as an antenna gain unit to
> 1
> GHz and above will change their beliefs. 

Antenna theory sometimes becomes like religion for many.

>Getting the antenna
> manufacturers
> to properly report the gain of their products is quite another thing. 

It is a good thing to have some standard that figures are reported by to
lower the confusion factor.

> As
> previous posters have mentioned, some popular antennas are junk that has
> never been properly tested on an antenna range, resulting in ridiculously
> inflated and undocumented claims of performance. 

Some of the prominent manufacturers do not have a range to do testing but
that doesn't necessarily make them junk. Some very good performing antennas
come out of those factories and a few duds also.

73
Gary K4FMX

If clueless buyers
> believe
> the hype, nothing is likely to change. That's a shame- but hey, it's the
> American Way!
> 
> 73, Eric Lemmon WB6FLY
> 



 

RE: [Repeater-Builder] Delta SX Deviation Setup

[Jeff DePolo]

> There is also a pot for modulating the VCO ...

Sorry.  That should have been "a pot for modulating the reference
oscillator".

RE: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd

[Gary Schafer]

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Eric Lemmon
> Sent: Tuesday, February 20, 2007 1:21 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Antenna Gain Specification - dBi versus dBd
> 
> The Telecommunications Industry Association, an international organization
> which develops standards to which nearly all countries of the world have
> subscribed, has already taken steps to correct the misleading practice of
> indiscriminately using dBi where dBd is appropriate.
> 
> According to TIA-329-C, published in 2003, base station antenna gain for
> less than 1 GHz shall expressed in dBd using a dipole antenna as a
> reference.  Antenna gain for 1 GHz and above shall be expressed in dBi
> using
> a theoretical isotropic radiator as a reference.  There are no exceptions.
> So, why are some manufacturers still using dBi for their 2m and 70cm
> antennas?  

Unfortunately dBd is not a cure all. Dbi is the true way to compare antennas
however not always the most convenient. One problem with dBi is that it
assumes free space. The dBd also assumes free space but is impossible to
test in true free space. When you get into the lower frequencies it becomes
more of a problem.


>There are probably several answers to that question, such as:
> 
> 1.  Perhaps most antenna buyers don't know the difference between dBi and
> dBd.
> 2.  Perhaps most antenna buyers believe whatever the ad copy says.
> 3.  Perhaps the company owner is an old-school believer that dBi is the
> only
> "true" gain unit.
> 4.  Perhaps the antenna designer knows about TIA-329-C, but chooses to
> ignore it.
> 
> It should be obvious that microwaves, which begin around 1 GHz, behave a
> lot
> like light and can be focused with a parabolic reflector.  Short radio
> waves
> are easy to visualize as being generated by a point source, very much like
> a
> bulb in a parabolic flashlight reflector.  Such point sources can be
> easily
> expressed as isotropic radiators, and the leap to dBi is logical. 


There is nothing unique about 1GHz over the lower frequencies being like
light waves.


> The
> wavelength of lower-frequency waves in the VHF and UHF spectra are not
> point
> sources, and it is illogical to expend any effort "converting" from one
> reference to the other.  

Neither are sources above 1GHz "point sources" any more than a 1 MHz signal
is. It is all a matter of scale. 

>As several others have pointed out, there is
> about
> 2.14 dB difference between the absolute gain expressed as dBi and that
> expressed as dBd.

This is only in free space.


> 
> Unfortunately, there will always be some "fringe group" that will argue
> until the end of time that dBi is the Nirvana of antenna gain expression.
> I
> doubt that the decision by the TIA to limit dBi as an antenna gain unit to
> 1
> GHz and above will change their beliefs.  

Antenna theory sometimes becomes like religion for many.

>Getting the antenna
> manufacturers
> to properly report the gain of their products is quite another thing. 

It is a good thing to have some standard that figures are reported by to
lower the confusion factor.

> As
> previous posters have mentioned, some popular antennas are junk that has
> never been properly tested on an antenna range, resulting in ridiculously
> inflated and undocumented claims of performance. 

Some of the prominent manufacturers do not have a range to do testing but
that doesn't necessarily make them junk. Some very good performing antennas
come out of those factories and a few duds also.

73
Gary  K4FMX

 If clueless buyers
> believe
> the hype, nothing is likely to change.  That's a shame- but hey, it's the
> American Way!
> 
> 73, Eric Lemmon WB6FLY
> 

RE: [Repeater-Builder] Antenna dBd Vs dBd

[Gary Schafer]

Good article Jim.

Beware of some things that you read on the web though. For example an
article on antennas in wikipida says that by using a folded dipole rather
than a regular dipole "increases the radiation resistance" by a factor of 4.
While the folded dipole does provide for a higher feed point resistance it
does NOT increase the radiation resistance.

73
Gary  K4FMX

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Jim Cicirello
> Sent: Tuesday, February 20, 2007 7:57 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Antenna dBd Vs dBd
> 
> I found this article on Antenna dBd Vs dBi that explains why some
> antennas show more gain than others. This is because the gain used in
> measuring some antennas is 2.15 dB more when expressed in dBi.
> 
> http://www.maxstream.net/support/knowledgebase/article.php?kb=146
> 
> Antenna Gain: dBi vs. dBd Decibel Detail
> Antenna gain is measured in either dBi or dBd.
> 
> It is important to note that antenna gain is different than amplifier
> gain. Antennas do not have a power source that allows the antenna to
> create additional energy to boost the signal. An antenna is similar to
> a reflective lens in principle - it takes the energy available from
> the source and focuses it over a wider or narrower area.
> 
> Antenna gain is then a measure of the amount of focus that an antenna
> can apply to the incoming signal relative to one of two reference
> dispersion patterns. MaxStream specifies all antenna gains in dBi.
> 
> dBi is the amount of focus applied by an antenna with respect to an
> "Isotropic Radiator" (a dispersion pattern that radiates the energy
> equally in all directions onto an imaginary sphere surrounding a point
> source). Thus an antenna with 2.1 dBi of gain focuses the energy so
> that some areas on an imaginary sphere surrounding the antenna will
> have 2.1 dB more signal strength than the strength of the strongest
> spot on the sphere around an Isotropic Radiator.
> 
> dBd refers to the antenna gain with respect to a reference dipole
> antenna. A reference dipole antenna is defined to have 2.15 dBi of
> gain. So converting between dBi and dBd is as simple as adding or
> subtracting 2.15 according to these formulas:
> 
> * dBi = dBd + 2.15
> * dBd = dBi - 2.15
> 
> Specifying antenna gain in dBd means that the antenna in question has
> the ability to focus the energy x dB more than a dipole.
> 
> Beam Width
> Because higher gain antennas achieve the extra power by focusing in on
> a smaller area it is important to remember that the greater the gain,
> the smaller the area covered as measured in degrees of beam width
> (think of an adjustable beam flashlight). In many cases a high gain
> antenna is a detriment to the system performance because the system
> needs to have reception over a large area.
> 
> Hope this helps, it helped me understand better what some Mfg may be
> using.
> 
> 73 JIM  KA2AJH
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 

RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Ken Arck]

At 07:29 AM 2/20/2007, you wrote:



>Ah, the gold old days, when men armed with a drill and Greenlee punch
>thought nothing of putting holes in their roofs, fearing not the Wrath of
>Wife.

<---When I bought my new Mustang last year, within 24 hours of 
bringing it home, I installed a genuine NMO mount in the trunk lid. 
Of course, I've always sworn by using Greenlee punches for the hole 
too (none of those stepped drill bits for me!)

My wife didn't even question me, other than "what took you so long"?

Ken
--
President and CTO - Arcom Communications
Makers of the world famous RC210 Repeater Controller and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net

RE: [Repeater-Builder] Delta SX Deviation Setup

[Jeff DePolo]

> I'm presently setting up 4 Delta SX UHF Transceivers as Tx'ters for a 
> repeater system. I have completed the mod and am presently trying to 
> tune radios. The problem I'm having is that my dev is up to about 9.8 
> kHz. My service manual says to adjust R237 (Dev Adj). The 
> radio that I 
> am working on does not have R237.

There are several revisions to the Delta-S and Delta-SX TRS boards; the
component labels and locations may be different than shown in your manual.

The voice deviation pot should be hidden under the shield covering up the
synthesizer/TRS area of the board (the rear compartment as viewed with front
of the radio toward you).  The pot is accessible through a hole in the
shield.  It's along the edge of the compartment closest to the front of the
radio, a little right of center.  The pot is adjusted with a hex diddle
stick.  Usually these pots have either a white or red plastic cap on them
(similiar to the pots used for setting the level of volume-squelch high, and
for setting power output in the PA); you should be able to see it through
the shield cover if you look with a flashlight.

There is also a pot for modulating the VCO (for low frequencies/DPL), which
is in the upper-right, but shouldn't normally need to be adjusted unless
you're using DPL, in which case, follow the procedure in the manual.

--- Jeff


 

RE: [Repeater-Builder] Re: Band Pass Duplexer Tuning

[Gary Schafer]

Like Ken said; all 3 ports need to be terminated in 50 ohms when tuning. A
signal generator is usually fairly close to 50 ohms, a receiver may or may
not be, usually not. The unused port at the time needs a 50 ohm load. 
The best way is to use a 6 db pad on gen and rec sides while tuning.

But what may be the worst problem is you may be trying to use it too far
from the design frequency. You have no way to tune the loops on those units.
Also be sure you haven't reversed the tx and rx frequencies as the loops are
tuned internally to pass a frequency only on one side of the notch.

73
Gary  K4FMX

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of fxbuilder
> Sent: Tuesday, February 20, 2007 9:49 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: Band Pass Duplexer Tuning
> 
> Ok... So I've tuned this duplexer as a notch device.  Put a 2 watt
> handheld into a dummy load and watt meter (not in that order mind you)
> and it seems to reject the corresponding frequencies.  My question now
> is... Why did my swr jump from 1:1.3 to 1:3.  Do I need to re-tweek
> it?  Also I'm noticing a huge power loss when measured before and
> after the duplexer. Talking 30 watts down to below 10 watts. Any
> suggestions. Perhaps it is time to check the cables etc?  Thanks for
> all the help in the past.
> Craig
> 
> 
> 
> 
> 
> --- In Repeater-Builder@yahoogroups.com, "Gary Schafer"
> <[EMAIL PROTECTED]> wrote:
> >
> > Lots of the small mobile duplexers (notch type) have fixed
> capacitors inside
> > and you can only adjust the cavity tuning, which tunes the notch.
> >
> > This type duplexer is limited in how far from the design frequency
> you can
> > tune it as the capacitors are fixed. The cavities will tune but the loss
> > goes.
> >
> > 73
> > Gary  K4FMX
> >
> > > -Original Message-
> > > From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> > > [EMAIL PROTECTED] On Behalf Of fxbuilder
> > > Sent: Friday, February 16, 2007 5:09 PM
> > > To: Repeater-Builder@yahoogroups.com
> > > Subject: [Repeater-Builder] Re: Band Pass Duplexer Tuning
> > >
> > > I emailed the place I bought it from and that is what I was told.
> > > Band Pass. No caps on it for notch tuning as on celwave.  Am I missing
> > > something here?
> > > Craig
> > >
> > >
> > >
> > >
> > > --- In Repeater-Builder@yahoogroups.com, Ken Arck  wrote:
> > > >
> > > > At 01:53 PM 2/16/2007, you wrote:
> > > >
> > > > >There is a great article on this site about tuning a notch
> duplexer by
> > > > >Kevin. Can similar methods be used for tuning a mobile 6 can band
> > > > >pass duplexer? Is there an article that I missed that explains
> it as
> > > > >easily? I need to re-tune and could use the help. I think I
> know how
> > > > >but thought I'd check.
> > > >
> > > >  > > >
> > > > Ken
> > > >
> > >
> --
> > > 
> > > > President and CTO - Arcom Communications
> > > > Makers of the world famous RC210 Repeater Controller and
> accessories.
> > > > http://www.arcomcontrollers.com/
> > > > Authorized Dealers for Kenwood and Telewave and
> > > > we offer complete repeater packages!
> > > > AH6LE/R - IRLP Node 3000
> > > > http://www.irlp.net
> > > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> >
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 

Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Jim B.]

Jeff DePolo wrote:
>> Oh, and 'mag mounts' didn't really exist much then...you 
>> either mounted 
>> the antenna in a hole, or you didn't have an antenna.
> 
> Ah, the gold old days, when men armed with a drill and Greenlee punch
> thought nothing of putting holes in their roofs, fearing not the Wrath of
> Wife.

ROFL!
-- 
Jim Barbour
WD8CHL

RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Jeff DePolo]

> Oh, and 'mag mounts' didn't really exist much then...you 
> either mounted 
> the antenna in a hole, or you didn't have an antenna.

Ah, the gold old days, when men armed with a drill and Greenlee punch
thought nothing of putting holes in their roofs, fearing not the Wrath of
Wife.

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

[twoway_tech]

Well, keep me posted on your findings with these things... I have a
few laying around that I already have Xtals for and want to get going.
I'll let you know if I find anything new.


-Jordan 

--- In Repeater-Builder@yahoogroups.com, "ka3hsw" <[EMAIL PROTECTED]> wrote:
>
> --- In Repeater-Builder@yahoogroups.com, "twoway_tech"  
> wrote:
> >
> > Well, Speaking of EFJ PPLs, has anyone accually performed the repeater
> >  mods that are descibed on the repeater builder page? I have done one
> > radio, but I am getting RF into the receiver. Jim Sharp (the author)
> > mentions putting a shield around Q1, but the transistors are not
> > labeled that way. I don't really see any EASY way to install any
> > shield that would do much good due to the trace layout on the board.
> 
> [snip]
> 
> Haven't done one yet, but have been studying the docs and, according to 
> the block diagram and schematic, the first RF amp is actually Q201. 
> There is a picture of where to solder the shield in the "updated-ppl-
> board.doc" file, linked from the conversion page.  It goes on the foil 
> side of the board, almost dead-center side-to-side, about 1/4 of the 
> way forward from the rear edge.
> 
> George, KA3HSW / WQGJ413
>

[Repeater-Builder] Delta SX Deviation Setup

[lewisdoucet]

I'm presently setting up 4 Delta SX UHF Transceivers as Tx'ters for a 
repeater system. I have completed the mod and am presently trying to 
tune radios. The problem I'm having is that my dev is up to about 9.8 
kHz. My service manual says to adjust R237 (Dev Adj). The radio that I 
am working on does not have R237. The Deltas that I have were in use in 
Canada by the RCMP and purchased as surplus. I built an Eeprom writer 
which appears to work okay. I also installed a four dip s/w to allow me 
to use 16 channels. The freq I programmed are 420.xxx and the Delta is 
a 403-430 MHz 35 W. For my application I have decreased O/P to 10 W. My 
freq error is less than 200 Hz. Anyone know how to adjust Dev without 
R237. I'm not new to electronics as I was a sonar technician in the 
Canadian Navy for 21 years but I am very new to 2 way radios. Any help 
would greatly be appreciated.

Re: [Repeater-Builder] Moto Moxy help!

[George Henry]

Crud...  I already shipped it out, with the promise that a manual would 
follow shortly.  I'm pretty sure it was 55 watts, though.

I suspect that I may have sent the full manual along with another Moxy I 
sold a couple of years ago, though I thought I kept a copy of the alignment 
procedure for myself.  If you can at least provide that much, it would be 
greatly appreciated.  (IIRC, the PA tuneup was simply to adjust the trimmer 
caps, in order, for maximum RF out, then set the desired output power with 
the power set pot on the exciter)

George, KA3HSW / WQGJ413


- Original Message - 
From: "Eric Lemmon" <[EMAIL PROTECTED]>
To: 
Sent: Monday, February 19, 2007 8:04 PM
Subject: RE: [Repeater-Builder] Moto Moxy help!


> George,
>
> If you can provide the complete model number, I'll see if I have
> documentation for it.  My Moxy model list shows only 10, 20, and 45 watt
> PAs.  Are you certain it had a 55W PA?
>
> 73, Eric Lemmon WB6FLY
>
>
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:[EMAIL PROTECTED] On Behalf Of ka3hsw
> Sent: Monday, February 19, 2007 7:24 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Moto Moxy help!
>
> Arrg!!! I just sold an old high-band Moxy on eBay, and now can't
> seem to locate the service manual I promised to send with it
> Anybody got a scanned version? Mostly in need of the tuneup procedure
> (55-watt PA)
>
> Thanks!
>
> George, KA3HSW / WQGJ413
>
>
>

Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Jim B.]

Jeff DePolo wrote:

> There are a lot of unknown variables here, including, but not limited to the
> size of the ground plane the antennas were mounted on, their heights above
> the ground plane, the method of coupling to the ground plane (direct, mag
> mount, etc.), matching networks' efficiencies, etc..  And more importantly,
> was the 4 dB gain a peak value, or at 0 degrees elevation?  
> 
> Typically a 5/8 wave over a perfect ground plane should be a little more
> than 3 dB better than a 1/4 wave on the horizon, but with so many unknowns
> and so much variability in mobile installations, there doesn't seem to be a
> definitive conclusion to be drawn here.  Maybe Jim can provide more detail.
> 
>   --- Jeff

Yes...this was actually mounted dead center in the roof of a car 
(remember this was around 1966-68, the car was a 65 or 66 Impala-BIG 
roof) and measurements were taken and at the same height as the antenna. 
I don't remember the distance from the car however, probably at least 
30', maybe as much as 100'.

Oh, and 'mag mounts' didn't really exist much then...you either mounted 
the antenna in a hole, or you didn't have an antenna.

-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur

[Jim B.]

Gary Schafer wrote:

>> Measured on their range-they used to be based in Cleveland, and my
>> father was one of the designers.
>> (anybody here remember the PRO-27JR 27Mhz antenna? Or the original 4BTV?)
>> --
>> Jim Barbour
>> WD8CHL
>>
> 
> With all due respect to your father Jim, I think that 4 db of gain is
> wishful thinking. A 5/8 wave length antenna theoretically is a little over 3
> db and in real life 3 db is seldom realized. If I am not mistaken a .64
> wavelength would have at most a tenth of a db advantage over a 5/8 antenna.
>  
> 73
> Gary  K4FMX

Yeah-right-ok...

-- 
Jim Barbour
WD8CHL

RE: [Repeater-Builder] Re: Antenna gain specs

[Gary Schafer]

Can you name any of the two way antenna manufacturers that do?

73
Gary  K4FMX

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Ron Wright, Skywarn Coodinator
> Sent: Tuesday, February 20, 2007 8:52 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: Antenna gain specs
> 
> Gary,
> 
> Most of the commerical guys do have test ranges and some very
> detailed and well engineered.
> 
> Most common below 1 GHz antennas were around long before computers
> like the PC were avialable and their technology, although sound and
> good, are old, go back into the 50s.
> 
> Some of the broadcast guys are really getting serious.  They have all
> kinds of ways of looking at antenna performance like just measuring
> the current distribution on the antenna elements to determine
> performance.  A broadcast antenna must meet some FCC certification
> for performance/gain/pattern before it can be used because ERP is the
> standard for power.
> 
> There has been lots of advancement in computer modeling and bet many
> not so good manufactures do use computer modeling as you said.
> 
> 73, ron, n9ee/r
> 
> 
> 
> >
> > It is also interesting to note that hardly any of the manufacturers
> of two
> > way antennas actually have an antenna test range or have ever
> tested the
> > antennas on a range. Most all the patterns that you see in the
> catalogs are
> > computer generated.
> >
> > 73
> > Gary  K4FMX
> >
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 

Re: [Repeater-Builder] Re: Antenna gain specs

[Jim B.]

Paul Holm wrote:
> Reading the replies that mentioned gain specs, I can't help but think of our 
> last ham club meeting.  An older member persuaded the club to replace the 
> VHF repeater antenna with a Diamond X500HNA rather than a DB-224 because the 
> Diamond "has 8.3 dB gain".

And even worse is that the rest of the club was stupid enough to listen...

I got a story about a club here and link receivers...I've got a box with 
3 UHF HT90's in it, rocked up ready to go, that I got stuck with the 
bill on after they decided to put in ham-grade rx's instead.

-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Statistics

[Jim B.]

Mike Morris WA6ILQ wrote:

> And as of today we have 3402 members
> 
> Mike WA6ILQ

Wow...pretty impressive!
You guys all deserve a lot of congrats for putting this together and 
making it the resource it is!
I remember Kevin making comments about how the list just passed 500, 
800, then 1000...my my...
-- 
Jim Barbour
WD8CHL

Re: [Repeater-Builder] Re: Band Pass Duplexer Tuning

[Ken Arck]

At 06:49 AM 2/20/2007, you wrote:

>Ok... So I've tuned this duplexer as a notch device. Put a 2 watt
>handheld into a dummy load and watt meter (not in that order mind you)
>and it seems to reject the corresponding frequencies. My question now
>is... Why did my swr jump from 1:1.3 to 1:3. Do I need to re-tweek
>it? Also I'm noticing a huge power loss when measured before and
>after the duplexer. Talking 30 watts down to below 10 watts. Any
>suggestions. Perhaps it is time to check the cables etc? Thanks for
>all the help in the past.

<---What did you do with the 3rd port during your tuning procedure? 
When you tune a duplexer, did you MUST present a 50 ohm load on ALL 3 
ports. This typically means using 3 (or 6) dB pads on all ports during tuning.

Since yours is showing excessive loss and bad VSWR, my bet is you 
left the 3rd port unterminated and didn't use pads on at least the 
Port to which the radio was connected.

Ken
--
President and CTO - Arcom Communications
Makers of the world famous RC210 Repeater Controller and accessories.
http://www.arcomcontrollers.com/
Authorized Dealers for Kenwood and Telewave and
we offer complete repeater packages!
AH6LE/R - IRLP Node 3000
http://www.irlp.net

[Repeater-Builder] Re: Band Pass Duplexer Tuning

[fxbuilder]

Ok... So I've tuned this duplexer as a notch device.  Put a 2 watt
handheld into a dummy load and watt meter (not in that order mind you)
and it seems to reject the corresponding frequencies.  My question now
is... Why did my swr jump from 1:1.3 to 1:3.  Do I need to re-tweek
it?  Also I'm noticing a huge power loss when measured before and
after the duplexer. Talking 30 watts down to below 10 watts. Any
suggestions. Perhaps it is time to check the cables etc?  Thanks for
all the help in the past.
Craig





--- In Repeater-Builder@yahoogroups.com, "Gary Schafer"
<[EMAIL PROTECTED]> wrote:
>
> Lots of the small mobile duplexers (notch type) have fixed
capacitors inside
> and you can only adjust the cavity tuning, which tunes the notch.
> 
> This type duplexer is limited in how far from the design frequency
you can
> tune it as the capacitors are fixed. The cavities will tune but the loss
> goes.
> 
> 73
> Gary  K4FMX
> 
> > -Original Message-
> > From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> > [EMAIL PROTECTED] On Behalf Of fxbuilder
> > Sent: Friday, February 16, 2007 5:09 PM
> > To: Repeater-Builder@yahoogroups.com
> > Subject: [Repeater-Builder] Re: Band Pass Duplexer Tuning
> > 
> > I emailed the place I bought it from and that is what I was told.
> > Band Pass. No caps on it for notch tuning as on celwave.  Am I missing
> > something here?
> > Craig
> > 
> > 
> > 
> > 
> > --- In Repeater-Builder@yahoogroups.com, Ken Arck  wrote:
> > >
> > > At 01:53 PM 2/16/2007, you wrote:
> > >
> > > >There is a great article on this site about tuning a notch
duplexer by
> > > >Kevin. Can similar methods be used for tuning a mobile 6 can band
> > > >pass duplexer? Is there an article that I missed that explains
it as
> > > >easily? I need to re-tune and could use the help. I think I
know how
> > > >but thought I'd check.
> > >
> > >  > >
> > > Ken
> > >
> >
--
> > 
> > > President and CTO - Arcom Communications
> > > Makers of the world famous RC210 Repeater Controller and
accessories.
> > > http://www.arcomcontrollers.com/
> > > Authorized Dealers for Kenwood and Telewave and
> > > we offer complete repeater packages!
> > > AH6LE/R - IRLP Node 3000
> > > http://www.irlp.net
> > >
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > Yahoo! Groups Links
> > 
> > 
> >
>

RE: [Repeater-Builder] Re: station master bandwidth?

[Gary Schafer]

Keep in mind that there are two (or more) ways to measure antenna band
width. One being swr band width and another being gain band width. One
doesn't necessarily follow the other.
What is advertised mostly is swr band width.

73
Gary  K4FMX

> -Original Message-
> From: Repeater-Builder@yahoogroups.com [mailto:Repeater-
> [EMAIL PROTECTED] On Behalf Of Ron Wright, Skywarn Coodinator
> Sent: Tuesday, February 20, 2007 9:03 AM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: station master bandwidth?
> 
> Ben,
> 
> The Phelps Dodge/Cel Wave and now Cel Wave/? had 8 Mhz.
> 
> One thing to keep in mind.  The 150-160 version had 6 dbd gain, but due
> to the fiber glass enclosure being only so long one element had to be
> removed in the 140-150 MHz Ham version so gain was rated at 5.1 dbd.
> This was from long time ago and think still the same.
> 
> I really think most of these antennas are made for a band, not a
> frequency.  Like 150-160, 140-150, etc.  So if you buy one you will get
> off the shelf version, not one cut for your freq.  Many suppliers have
> a stock of them.  If one looks at the SWR graph one sees a range and
> 1.5:1 seems to be the standard to mark the band limits.  Some might
> actually cut for the actual ordered freq like with duplexers.
> 
> 73, ron, n9ee/r
> 
> 
> 
> 
> --- In Repeater-Builder@yahoogroups.com, "w4wsm" <[EMAIL PROTECTED]> wrote:
> >
> > Hi,
> >
> > Any idea what kind of bandwidth a full size station master would have?
> > VHF marked 153.XX...should it go down into the 2 meter band or are
> > they very narrow?
> >
> > Ben
> >
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 

[Repeater-Builder] Re: Statistics

[Ron Wright, Skywarn Coodinator]

Mike,

I read the e-mails on the board and do not send to my personal 
account.  This board gets a lot of them and I have found with yahoo 
by the 3rd reply the subject has gone away.

Starts like "what is a good repeater antenna for 2 meters"
reply #1 "well in Atlanta, GA we used a DB224 side mounted on 180 ft 
Rohn 25".
reply #2 "you lived in Atanta, when??"
reply #3 "do you have any Rohn 25 left for sale?"
reply #4 "my wife liked the DB224...we use one for the green beans in 
our garden."

This is not just this board, but about all yahoo boards.  I do like 
this board very much for it does provide a most educational source 
for repeaters, about the best around.  I recommend to all needing 
info on repeater building.

See even I changed the subject some, hi.

73, ron, n9ee/r



--- In Repeater-Builder@yahoogroups.com, Mike Morris WA6ILQ 
<[EMAIL PROTECTED]> wrote:
>
> Recently I did some research on the membership statistics for this 
group.
> 
> Here's some interesting info:
> 
> We have 3,393 members.
> 
> 556 are in "Daily Digest" mode.
> 
> 883 are in "Individual Emails" mode
> 
> 275 are in "Special Notices" mode - i.e. they read the mail via the 
> YahooGroups web site, and if the owner or moderators send out a 
> special notice they will get it in their normal email (note that 
this 
> feature is almost never used here, in fact I can't remember the 
last 
> time it was used).
> 
> 1,679 are on "No Email" - i.e. they read the mail via the 
YahooGroups 
> web site and they have locked themselves out of special notices.
> 
> That last tidbit is very surprising to me.  I would have thought 
that 
> maybe 1/10 that many would go to the hassle of reading the mail 
> through a web browser.
> 
> 1694 are in "Fully Featured" mode, the rest are either in "Default" 
> or "Traditional" mode.  The "Default" mode ones haven't made a 
choice 
> yet.  Yahoo may make one for them at some point.
> 
> The above is from a quick look at the Excel spreadsheet.
> I'm not a guru in Excel number crunching, and I didn't have a 
reason 
> to go poking around any further.
> 
> Mike WA6ILQ
>

[Repeater-Builder] Re: station master bandwidth?

[Ron Wright, Skywarn Coodinator]

Ben,

The Phelps Dodge/Cel Wave and now Cel Wave/? had 8 Mhz.

One thing to keep in mind.  The 150-160 version had 6 dbd gain, but due 
to the fiber glass enclosure being only so long one element had to be 
removed in the 140-150 MHz Ham version so gain was rated at 5.1 dbd.  
This was from long time ago and think still the same.

I really think most of these antennas are made for a band, not a 
frequency.  Like 150-160, 140-150, etc.  So if you buy one you will get 
off the shelf version, not one cut for your freq.  Many suppliers have 
a stock of them.  If one looks at the SWR graph one sees a range and 
1.5:1 seems to be the standard to mark the band limits.  Some might 
actually cut for the actual ordered freq like with duplexers.

73, ron, n9ee/r




--- In Repeater-Builder@yahoogroups.com, "w4wsm" <[EMAIL PROTECTED]> wrote:
>
> Hi,
> 
> Any idea what kind of bandwidth a full size station master would have?
> VHF marked 153.XX...should it go down into the 2 meter band or are
> they very narrow?
> 
> Ben
>

[Repeater-Builder] Re: Antenna gain specs

[Ron Wright, Skywarn Coodinator]

Mark,

Right on the Diamond package is dbd, not dbi.  However, I do not 
believe if in dbi.

73, ron, n9ee/r



--- In Repeater-Builder@yahoogroups.com, "N9WYS" <[EMAIL PROTECTED]> wrote:
>
> I believe Diamond uses gain over **isotropic** (dBi) for their 
rating
> specs... which might account for the extra ~2.2dB.  
> 
> (If memory serves me the difference between dBi and dBd is about 
2.2 - yes?)
> 
> This is one reason to be careful about what the respective company 
is using
> for their comparison... gain vs Isotrpoic or gain vs Dipole.
> 
> Mark - N9WYS
>  
> -Original Message-
> From: Repeater-Builder@yahoogroups.com On Behalf Of Laryn Lohman
> 
> Yup, Paul, you've caught on.
> 
> Diamond must be good; very good.  They've bent the laws of physics
> again.  Diamond's 18 ft. long antenna has more  than a DB
> Products, Sinclair, etc., which are actually slightly longer.  8.3db
> gain over what?  I'm here to tell you, in my humble opinion, that 
the
> Diamond's actual gain over a dipole is closer to 6dbd. 
> 
> Laryn K8TVZ
>

[Repeater-Builder] Re: Antenna gain specs

[Ron Wright, Skywarn Coodinator]

Gary,

Most of the commerical guys do have test ranges and some very 
detailed and well engineered.

Most common below 1 GHz antennas were around long before computers 
like the PC were avialable and their technology, although sound and 
good, are old, go back into the 50s.

Some of the broadcast guys are really getting serious.  They have all 
kinds of ways of looking at antenna performance like just measuring 
the current distribution on the antenna elements to determine 
performance.  A broadcast antenna must meet some FCC certification 
for performance/gain/pattern before it can be used because ERP is the 
standard for power.

There has been lots of advancement in computer modeling and bet many 
not so good manufactures do use computer modeling as you said.

73, ron, n9ee/r



> 
> It is also interesting to note that hardly any of the manufacturers 
of two
> way antennas actually have an antenna test range or have ever 
tested the
> antennas on a range. Most all the patterns that you see in the 
catalogs are
> computer generated.
> 
> 73
> Gary  K4FMX
>

[Repeater-Builder] Re: Antenna Gain Specification - dBi versus dBd

[Ron Wright, Skywarn Coodinator]

Eric,

I think the reason antenna manufactures use dbi over dbd is dbi is 
higher...the higher the spec the more impressed is the customer.  
Most Hams probably do not know how to read the spec reference, dbi or 
dbd.  They see db.

When a Ringo-Ranger is advertised in Ham magazines it has 6 db gain.  
When advertised in commerical publications/catalogs it has 4.5 db 
gain...same antenna, same part number.

I think those working with commerical and other professional systems 
know the specs and look for details.  When they see db they want to 
know dbi or dbd and maybe how determined...prove your spec.  

Could never understand why a Diamond long 18 ft dual band antenna has 
about 8 dbd on VHF/11 dbd on UHF when a commerical antenna like the 
Super Station Master or DB224 has 6 db.  Think the commerical people 
know why, not, hi.

QST for a long time refused to print gain specs in the ads for they 
knew most was smoke.

73, ron, n9ee/r



--- In Repeater-Builder@yahoogroups.com, "Eric Lemmon" <[EMAIL PROTECTED]> 
wrote:
>
> The Telecommunications Industry Association, an international 
organization
> which develops standards to which nearly all countries of the world 
have
> subscribed, has already taken steps to correct the misleading 
practice of
> indiscriminately using dBi where dBd is appropriate.
> 
> According to TIA-329-C, published in 2003, base station antenna 
gain for
> less than 1 GHz shall expressed in dBd using a dipole antenna as a
> reference.  Antenna gain for 1 GHz and above shall be expressed in 
dBi using
> a theoretical isotropic radiator as a reference.  There are no 
exceptions.
> So, why are some manufacturers still using dBi for their 2m and 70cm
> antennas?  There are probably several answers to that question, 
such as:
> 
> 1.  Perhaps most antenna buyers don't know the difference between 
dBi and
> dBd.
> 2.  Perhaps most antenna buyers believe whatever the ad copy says.
> 3.  Perhaps the company owner is an old-school believer that dBi is 
the only
> "true" gain unit.
> 4.  Perhaps the antenna designer knows about TIA-329-C, but chooses 
to
> ignore it.
> 
> It should be obvious that microwaves, which begin around 1 GHz, 
behave a lot
> like light and can be focused with a parabolic reflector.  Short 
radio waves
> are easy to visualize as being generated by a point source, very 
much like a
> bulb in a parabolic flashlight reflector.  Such point sources can 
be easily
> expressed as isotropic radiators, and the leap to dBi is logical.  
The
> wavelength of lower-frequency waves in the VHF and UHF spectra are 
not point
> sources, and it is illogical to expend any effort "converting" from 
one
> reference to the other.  As several others have pointed out, there 
is about
> 2.14 dB difference between the absolute gain expressed as dBi and 
that
> expressed as dBd.
> 
> Unfortunately, there will always be some "fringe group" that will 
argue
> until the end of time that dBi is the Nirvana of antenna gain 
expression.  I
> doubt that the decision by the TIA to limit dBi as an antenna gain 
unit to 1
> GHz and above will change their beliefs.  Getting the antenna 
manufacturers
> to properly report the gain of their products is quite another 
thing.  As
> previous posters have mentioned, some popular antennas are junk 
that has
> never been properly tested on an antenna range, resulting in 
ridiculously
> inflated and undocumented claims of performance.  If clueless 
buyers believe
> the hype, nothing is likely to change.  That's a shame- but hey, 
it's the
> American Way!
> 
> 73, Eric Lemmon WB6FLY
>

Re: [Repeater-Builder] Problems With Diamond NR73BNMO

[Kevin Custer]

Tony L. wrote:
> My Diamond NR73BNMO stopped working on 70cm.  Tx & rx are both fine on 
> 2 meters, but the antenna will not tx or rx on 70 cm.
>
> I swapped the antenna with a spare, and everything works fine with the 
> replacement antenna.
>
> Any ideas?
>   

Take it apart and look to see if water found its way to the loading 
coil.  Acid rain, or water and RF, will eat the leads of the small 
capacitors off.  If lightning hit close, the small caps could be blown 
off, leaving two leads and a small puff of ceramic dirt behind.

Mobile antennas are tough to get apart without ruining them.  Good luck 
and let us know if the operation was a success (or failure).

Kevin C.

[Repeater-Builder] Antenna dBd Vs dBd

[Jim Cicirello]

I found this article on Antenna dBd Vs dBi that explains why some
antennas show more gain than others. This is because the gain used in
measuring some antennas is 2.15 dB more when expressed in dBi.

http://www.maxstream.net/support/knowledgebase/article.php?kb=146

Antenna Gain: dBi vs. dBd Decibel Detail
Antenna gain is measured in either dBi or dBd.
 
It is important to note that antenna gain is different than amplifier
gain. Antennas do not have a power source that allows the antenna to
create additional energy to boost the signal. An antenna is similar to
a reflective lens in principle - it takes the energy available from
the source and focuses it over a wider or narrower area.
 
Antenna gain is then a measure of the amount of focus that an antenna
can apply to the incoming signal relative to one of two reference
dispersion patterns. MaxStream specifies all antenna gains in dBi.
 
dBi is the amount of focus applied by an antenna with respect to an
"Isotropic Radiator" (a dispersion pattern that radiates the energy
equally in all directions onto an imaginary sphere surrounding a point
source). Thus an antenna with 2.1 dBi of gain focuses the energy so
that some areas on an imaginary sphere surrounding the antenna will
have 2.1 dB more signal strength than the strength of the strongest
spot on the sphere around an Isotropic Radiator.
 
dBd refers to the antenna gain with respect to a reference dipole
antenna. A reference dipole antenna is defined to have 2.15 dBi of
gain. So converting between dBi and dBd is as simple as adding or
subtracting 2.15 according to these formulas:

* dBi = dBd + 2.15
* dBd = dBi - 2.15

Specifying antenna gain in dBd means that the antenna in question has
the ability to focus the energy x dB more than a dipole.

Beam Width
Because higher gain antennas achieve the extra power by focusing in on
a smaller area it is important to remember that the greater the gain,
the smaller the area covered as measured in degrees of beam width
(think of an adjustable beam flashlight). In many cases a high gain
antenna is a detriment to the system performance because the system
needs to have reception over a large area.

Hope this helps, it helped me understand better what some Mfg may be
using.

73 JIM  KA2AJH