Here is a problem that I'm having with my Diamond X700.
Hopefully someone can give me some advice on which antenna would suit
my needs best.

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.

Can anyone comment on the Decibel product? Any help and suggestions
would be appreciated.

Or if you can suggest any other antenna that could be used for
repeater use at my home.

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.


Go with the DB Products or any other comercial 4 bay dipole antenna. The
ones like Comet and Diamond are fine for some home applications . They
just will not stand up to being mounted on a tall windy repeater tower.
Hate to say it about a product but you bought expensive junk...

The antennna must be getting its gain numbers over a rubber duckey at ground
level. There is no way to get 9 db of gain with an antenna about 20 feet
long (omnidirectioal) . The 4 bay dipole antenna will give just under 6 db
over a dipole if it is correctly made. Colinear antennas will give even
less for that length .
Something around 5 dbd is more like it.

Check out the repeater builders group on Yahoo for information. Don't take
my word for it , I have only been keeping a repeater up for a little over 25
years.
Go he

http://www.kuggie.com/rbtip/

and click on the repeater builders technical info page.

BTW they do not think much of the lmr400 due to problems like you seem to be
having. The braid and the foil reportably flex in the wind and make that
kind of noise in a duplexed system. I am running a repeater that for the
last 2 years that has 100 feet of lmr400 on it and I am not noticing the
noise. It may take a rew years to develop as the brade loosens up . I don't
really know. I do know that if you have loose guy wires or other loose
hardware on the tower you will get the noise in the receiver when the
transmitter is on. I did have a guy wire problem one time . Tower is 100
feet of Rohn 25G With a stationmaster on top . The top guy wires on the
ground anchor had about 3 feet of loose ends. When the wind whipped the
ends back on the guy wire going to the top of the tower I had noise like
mad.

De KU4PT

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.


Go with the DB Products or any other comercial 4 bay dipole antenna. The
ones like Comet and Diamond are fine for some home applications . They
just will not stand up to being mounted on a tall windy repeater tower.
Hate to say it about a product but you bought expensive junk...

The antennna must be getting its gain numbers over a rubber duckey at ground
level. There is no way to get 9 db of gain with an antenna about 20 feet
long (omnidirectioal) . The 4 bay dipole antenna will give just under 6 db
over a dipole if it is correctly made. Colinear antennas will give even
less for that length .
Something around 5 dbd is more like it.

Check out the repeater builders group on Yahoo for information. Don't take
my word for it , I have only been keeping a repeater up for a little over 25
years.
Go he

http://www.kuggie.com/rbtip/

and click on the repeater builders technical info page.

BTW they do not think much of the lmr400 due to problems like you seem to be
having. The braid and the foil reportably flex in the wind and make that
kind of noise in a duplexed system. I am running a repeater that for the
last 2 years that has 100 feet of lmr400 on it and I am not noticing the
noise. It may take a rew years to develop as the brade loosens up . I don't
really know. I do know that if you have loose guy wires or other loose
hardware on the tower you will get the noise in the receiver when the
transmitter is on. I did have a guy wire problem one time . Tower is 100
feet of Rohn 25G With a stationmaster on top . The top guy wires on the
ground anchor had about 3 feet of loose ends. When the wind whipped the
ends back on the guy wire going to the top of the tower I had noise like
mad.

De KU4PT

You might want to test your theory by swapping to another, even smaller
antenna just to see if the problem goes away. I agree with the other
post that the Diamond is not as much gain as advertised and an exposed
dipole array is about the most omni gain you will find for the size.
Mike

wrote:
Here is a problem that I'm having with my Diamond X700.
Hopefully someone can give me some advice on which antenna would suit
my needs best.

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.

Can anyone comment on the Decibel product? Any help and suggestions
would be appreciated.

Or if you can suggest any other antenna that could be used for
repeater use at my home.

You might want to test your theory by swapping to another, even smaller
antenna just to see if the problem goes away. I agree with the other
post that the Diamond is not as much gain as advertised and an exposed
dipole array is about the most omni gain you will find for the size.
Mike

wrote:
Here is a problem that I'm having with my Diamond X700.
Hopefully someone can give me some advice on which antenna would suit
my needs best.

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.

Can anyone comment on the Decibel product? Any help and suggestions
would be appreciated.

Or if you can suggest any other antenna that could be used for
repeater use at my home.

wrote:

Here is a problem that I'm having with my Diamond X700.
Hopefully someone can give me some advice on which antenna would suit
my needs best.

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.

Can anyone comment on the Decibel product? Any help and suggestions
would be appreciated.

Or if you can suggest any other antenna that could be used for
repeater use at my home.


I have seen a suggestion of using the Hustler 2 meter base antenna as an
antenna for repeaters as they are fairly rugged. The person that was saying
this claimed that eventually the harness on the exposed four bay antennas
will deterioate and even though the SWR would look good the gain would go in
the dumper. The group that states the Hustler is good is the South East
Iowa Technical society. Use Google to look up SEITS and they have some
pointers for setting up repeaters.

Al Butler
ka0ies

wrote:

Here is a problem that I'm having with my Diamond X700.
Hopefully someone can give me some advice on which antenna would suit
my needs best.

Problem:

My Diamond X700 cost me $400. I'm using it for a VHF repeater
antenna.

The problem it causes is every now and then, I get gurgling noises and
crackling in the transmit and it takes out weak signals.

This problem may stay in a few days and be gone for a few days and
then come back again.

It is not my TX RX duplexer. That was already checked out.
I replaced my coax with LMR400. (75 ft. run)
I have even changed repeaters and get the same results.

Someone told me that the Diamond antennaes are NOT good in repeater
service because they whip around and the rods inside do get broken and
cause problems and will not show a bad SWR. My SWR is fine.

Anyone out here have the same problems that I'm having? Do you have
any suggestions on a proper antenna to use?

I do have one suggestion and that was to get a Decibel products DB 224
antenna. Their website shows it as 6 DB gain where my Diamond is 9
DB.
I'm afraid that I will lose my receive coverage with the lesser DB
gain.

Can anyone comment on the Decibel product? Any help and suggestions
would be appreciated.

Or if you can suggest any other antenna that could be used for
repeater use at my home.


I have seen a suggestion of using the Hustler 2 meter base antenna as an
antenna for repeaters as they are fairly rugged. The person that was saying
this claimed that eventually the harness on the exposed four bay antennas
will deterioate and even though the SWR would look good the gain would go in
the dumper. The group that states the Hustler is good is the South East
Iowa Technical society. Use Google to look up SEITS and they have some
pointers for setting up repeaters.

Al Butler
ka0ies

I have seen a suggestion of using the Hustler 2 meter base antenna as an
antenna for repeaters as they are fairly rugged. The person that was saying
this claimed that eventually the harness on the exposed four bay antennas
will deterioate and even though the SWR would look good the gain would go in
the dumper.

Ritchi & Al-

Gain isn't everything, but having a higher number sells antennas! Some
companys use the higher dBi number. Others use dBd which is 2.1 dB lower.
Although engineers are taught antennas from the isotropic point of view, I
believe it is an industry standard that the dipole be used as a reference for
VHF and UHF two-way radio antennas. The dipole certainly is more practical if
you want to measure gain.

I've used the Hustler G6-144 successfully, but don't consider them especially
rugged. The fiberglass deteriorates in the weather. Mine also got beat-up by
some tree limbs! I had the repeater on for several years and eventually
replaced the antenna with another G6-144.

Another repeater that used the G6-144 at a higher elevation (top of a city
water tower), had a couple ruined by lightning. The phasing coil just
vaporized in each case. After having problems with a Diamond, they switched to
a used commercial DB 4-dipole antenna, and have had excellent results. One
lightning strike took out some of the equipment but didn't seem to phase the
antenna.

If you go for the 4-dipole antenna, be sure to get the one with the phasing
harness INSIDE the mast. Otherwise you will probably have troubles with
deterioration, as Al noted.

73, Fred, K4DII

I have seen a suggestion of using the Hustler 2 meter base antenna as an
antenna for repeaters as they are fairly rugged. The person that was saying
this claimed that eventually the harness on the exposed four bay antennas
will deterioate and even though the SWR would look good the gain would go in
the dumper.

Ritchi & Al-

Gain isn't everything, but having a higher number sells antennas! Some
companys use the higher dBi number. Others use dBd which is 2.1 dB lower.
Although engineers are taught antennas from the isotropic point of view, I
believe it is an industry standard that the dipole be used as a reference for
VHF and UHF two-way radio antennas. The dipole certainly is more practical if
you want to measure gain.

I've used the Hustler G6-144 successfully, but don't consider them especially
rugged. The fiberglass deteriorates in the weather. Mine also got beat-up by
some tree limbs! I had the repeater on for several years and eventually
replaced the antenna with another G6-144.

Another repeater that used the G6-144 at a higher elevation (top of a city
water tower), had a couple ruined by lightning. The phasing coil just
vaporized in each case. After having problems with a Diamond, they switched to
a used commercial DB 4-dipole antenna, and have had excellent results. One
lightning strike took out some of the equipment but didn't seem to phase the
antenna.

If you go for the 4-dipole antenna, be sure to get the one with the phasing
harness INSIDE the mast. Otherwise you will probably have troubles with
deterioration, as Al noted.

73, Fred, K4DII

A 'commercial' antenna like the STATION MASTER cut for ham freqs is a much
better choice than a Diamond. It costs more, but you get what you pay for.

Richard in Boston, MA, USA
N1JDU