I am looking for recommendations for a dual band antenna that will serve two separate radios. The reason that I want to use a single antenna is that I have a limited number of mounting points for antennas. At present it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be Obeyed; to tolerate the use of both our home's gable ends and the chimney being used to support antennas. I am planning to replace my Diamond X-30 with a triband vertical for Six, Two, and .7 Meters. The chimney will then support a rotor aimed Two and .7 Meter beam. The second gable end will support the Two meter / Seventy Centimeter dual band vertical that I am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink Radio Message Server. The other radio will be a UHF D-STAR hotspot. I am willing to pay what is needed to to get the best antenna for this application but I don't want to waste money ineffectively. So the two meter radio will be in the 144 MHz portion of the band and I don't yet actually know were the D-STAR hotspot will be run. I have a DCI filter and diplexer to keep the two radios from actually knowing of each others existence. Since a hotspot is not supposed to be a terribly wide area installation I would imagine that I do not want an extremely high gain antenna but I am perfectly open to be reeducated on that. The difficulty is that I would guess that the Radio Message Server / Packet would benefit from as much horizontal gain as can be achieved. I have a home brewed collinear two meter J-Pole that has been a good performer on two meters and presents a low SWR on 440 MHz. I have yet to master antenna modeling but I would imagine; given all the warnings I have read on line; that it has poor radiation pattern on UHF. Is it likely to be too poor a performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for encouragement to do something that will be ineffective. Thank you in advance for any help you may be willing to offer.

--
Tom Horne W3TDH

On 3/11/2015 6:02 PM, Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve two separate radios. The reason that I want to use a single antenna is that I have a limited number of mounting points for antennas. At present it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be Obeyed; to tolerate the use of both our home's gable ends and the chimney being used to support antennas. I am planning to replace my Diamond X-30 with a triband vertical for Six, Two, and .7 Meters. The chimney will then support a rotor aimed Two and .7 Meter beam. The second gable end will support the Two meter / Seventy Centimeter dual band vertical that I am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink Radio Message Server. The other radio will be a UHF D-STAR hotspot. I am willing to pay what is needed to to get the best antenna for this application but I don't want to waste money ineffectively. So the two meter radio will be in the 144 MHz portion of the band and I don't yet actually know were the D-STAR hotspot will be run. I have a DCI filter and diplexer to keep the two radios from actually knowing of each others existence. Since a hotspot is not supposed to be a terribly wide area installation I would imagine that I do not want an extremely high gain antenna but I am perfectly open to be reeducated on that. The difficulty is that I would guess that the Radio Message Server / Packet would benefit from as much horizontal gain as can be achieved. I have a home brewed collinear two meter J-Pole that has been a good performer on two meters and presents a low SWR on 440 MHz. I have yet to master an
tenna modeling but I would imagine; given all the warnings I have read on line; that it has poor radiation pattern on UHF. Is it likely to be too poor a performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for encouragement to do something that will be ineffective. Thank you in advance for any help you may be willing to offer.

--
Tom Horne W3TDH


Tom,

There are a number of good antennas around. The problem is not going to
be the antenna, though - it will be separating the two radios. If you
transmit on one while both are connected to the antenna, you'll blow the
front end of the other.

You'll need either a coax switch/relay or some kind of filters to ensure
one does not get into the other. And even though we're talking VHF and
UHF, good filers which will provide the separation you need yet not
degrade the signal you want are expensive. If you're only talking one
frequency, maybe a couple of sets of duplexers will work - one set for
each band.

Of course, rf detecting coax switches will work - but you also then need
to ensure that both don't try to transmit at the same time - one or both
will be transmitting into an open circuit (depending on how you wire
them up).

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 3/11/2015 5:02 PM, Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will
serve two separate radios. The reason that I want to use a single
antenna is that I have a limited number of mounting points for
antennas. At present it will be hard for SWMBO; as in Rumpole's
spouse, She Who Must Be Obeyed; to tolerate the use of both our
home's gable ends and the chimney being used to support antennas. I
am planning to replace my Diamond X-30 with a triband vertical for
Six, Two, and .7 Meters. The chimney will then support a rotor aimed
Two and .7 Meter beam. The second gable end will support the Two
meter / Seventy Centimeter dual band vertical that I am asking for
help in selecting.

One radio will be a two meter packet node which will be used as a
Winlink Radio Message Server. The other radio will be a UHF D-STAR
hotspot. I am willing to pay what is needed to to get the best
antenna for this application but I don't want to waste money
ineffectively. So the two meter radio will be in the 144 MHz portion
of the band and I don't yet actually know were the D-STAR hotspot
will be run. I have a DCI filter and diplexer to keep the two radios
from actually knowing of each others existence. Since a hotspot is
not supposed to be a terribly wide area installation I would imagine
that I do not want an extremely high gain antenna but I am perfectly
open to be reeducated on that. The difficulty is that I would guess
that the Radio Message Server / Packet would benefit from as much
horizontal gain as can be achieved. I have a home brewed collinear
two meter J-Pole that has been a good performer on two meters and
presents a low SWR on 440 MHz. I have yet to master antenna modeling
but I would imagine; given all the warnings I have read on line; that
it has poor radiation pattern on UHF. Is it likely to be too poor a
performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for
encouragement to do something that will be ineffective. Thank you in
advance for any help you may be willing to offer.

-- Tom Horne W3TDH


Hi, Tom -

I did some quick, crude modelling of a vertically-polarized half-wave
(J-Pole) and it seems to have a pattern about as good on 70cm as on 2M.
There is a bit more energy radiated about 50 degrees above the horizon
on 70cm, but there seems to be plenty left at about 1.5 degrees (about
6.5dBi). I assumed an antenna height of 20 feet.

If it were me, I would try the J-Pole. However, you need to consider how
much time and effort it would take to change to a different antenna if
you are not happy.

73, John N1JLS

In article ,
Tom W3TDH wrote:

The other radio will be a UHF D-STAR hotspot.

Tom-

What kind of range are you trying to achieve with the hotspot? The
little antenna that came with a UHF DVAP covers my property fairly well,
just sitting on a table.

I connected it to a Larsen dual-band mag-mounted antenna stuck on top of
a filing cabinet, and get about a half mile range when mobile. The DVAP
puts out about a tenth of a Watt. I suspect it can hear the 50 Watt
mobile a lot further away.

If you want range, consider taking the DVAP with you and connecting to
the internet through a cellular modem or telephone. I'm considering
getting a D-HAP, which holds everything but the radio and the cellular
connection. http://www.portableuniversalpower.com/dhap/

73,
Fred
K4DII

On Thursday, March 12, 2015 at 12:20:57 PM UTC-4, Fred McKenzie wrote:
In article ,
Tom W3TDH wrote:

The other radio will be a UHF D-STAR hotspot.

Tom-

What kind of range are you trying to achieve with the hotspot? The
little antenna that came with a UHF DVAP covers my property fairly well,
just sitting on a table.

I connected it to a Larsen dual-band mag-mounted antenna stuck on top of
a filing cabinet, and get about a half mile range when mobile. The DVAP
puts out about a tenth of a Watt. I suspect it can hear the 50 Watt
mobile a lot further away.

If you want range, consider taking the DVAP with you and connecting to
the internet through a cellular modem or telephone. I'm considering
getting a D-HAP, which holds everything but the radio and the cellular
connection. http://www.portableuniversalpower.com/dhap/

73,
Fred
K4DII

Fred

I must confess that I am a little up in the air on the D-STAR hot spot issues. The hot spot is part of a club project that I would be hosting at my home. The club is using Motorola M120 radios at the low end of their power output which is around Twenty Five Watts I believe. The effort is intended to cover as much of our service area as is practical with Seventy Centimeter D-STAR coverage. The strange thing is that I am not a D-STAR user. I use the clubs centrally located analog repeater for my UHF coverage needs. I'm only hosting the local node in order to support the club effort.

Tom Horne W3TDH

On Wednesday, March 11, 2015 at 7:11:14 PM UTC-4, Brian Reay wrote:
Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve
two separate radios. The reason that I want to use a single antenna is
that I have a limited number of mounting points for antennas. At present
it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be
Obeyed; to tolerate the use of both our home's gable ends and the chimney
being used to support antennas. I am planning to replace my Diamond X-30
with a triband vertical for Six, Two, and .7 Meters. The chimney will
then support a rotor aimed Two and .7 Meter beam. The second gable end
will support the Two meter / Seventy Centimeter dual band vertical that I
am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink
Radio Message Server. The other radio will be a UHF D-STAR hotspot. I
am willing to pay what is needed to to get the best antenna for this
application but I don't want to waste money ineffectively. So the two
meter radio will be in the 144 MHz portion of the band and I don't yet
actually know were the D-STAR hotspot will be run. I have a DCI filter
and diplexer to keep the two radios from actually knowing of each others
existence. Since a hotspot is not supposed to be a terribly wide area
installation I would imagine that I do not want an extremely high gain
antenna but I am perfectly open to be reeducated on that. The difficulty
is that I would guess that the Radio Message Server / Packet would
benefit from as much horizontal gain as can be achieved. I have a home
brewed collinear two meter J-Pole that has been a good performer on two
meters and presents a low SWR on 440 MHz. I have yet to master antenna
modeling but I would imagine; given all the warnings I have read on line;
that it has poor radiation pattern on UHF. Is it likely to be too poor a
performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for
encouragement to do something that will be ineffective. Thank you in
advance for any help you may be willing to offer.

--
Tom Horne W3TDH

Diamond do a number of other antennas similar to the x30, essentially
longer, with more gain. I would suggest you look at their website and pick
one to match you budget, acceptable profile, etc.

It may be worth investing in another tribander, you may just want the third
band in the future and it will save another negotiation with Senior
Management. Or you could take my approach and have an XYL who is licensed
;-)

73
Brian
G8OSN/W8OSN

Brian

Thank you for the second tribander idea. I do not now have a 220 MHz base antenna. So using a tribander instead of a dual band antenna will add that additional bands worth of capability to me base station. Since I am very heavily involved in local EMCOMM preparation that is a very worthwhile thing to do. It must be a good day because I learned something new.

--
Tom Horne W3TDH

On Wednesday, March 11, 2015 at 8:15:54 PM UTC-4, Jerry Stuckle wrote:
On 3/11/2015 6:02 PM, Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve two separate radios. The reason that I want to use a single antenna is that I have a limited number of mounting points for antennas. At present it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be Obeyed; to tolerate the use of both our home's gable ends and the chimney being used to support antennas. I am planning to replace my Diamond X-30 with a triband vertical for Six, Two, and .7 Meters. The chimney will then support a rotor aimed Two and .7 Meter beam. The second gable end will support the Two meter / Seventy Centimeter dual band vertical that I am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink Radio Message Server. The other radio will be a UHF D-STAR hotspot. I am willing to pay what is needed to to get the best antenna for this application but I don't want to waste money ineffectively. So the two meter radio will be in the 144 MHz portion of the band and I don't yet actually know were the D-STAR hotspot will be run. I have a DCI filter and diplexer to keep the two radios from actually knowing of each others existence. Since a hotspot is not supposed to be a terribly wide area installation I would imagine that I do not want an extremely high gain antenna but I am perfectly open to be reeducated on that. The difficulty is that I would guess that the Radio Message Server / Packet would benefit from as much horizontal gain as can be achieved. I have a home brewed collinear two meter J-Pole that has been a good performer on two meters and presents a low SWR on 440 MHz. I have yet to master an
tenna modeling but I would imagine; given all the warnings I have read on line; that it has poor radiation pattern on UHF. Is it likely to be too poor a performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for encouragement to do something that will be ineffective. Thank you in advance for any help you may be willing to offer.

--
Tom Horne W3TDH


Tom,

There are a number of good antennas around. The problem is not going to
be the antenna, though - it will be separating the two radios. If you
transmit on one while both are connected to the antenna, you'll blow the
front end of the other.

You'll need either a coax switch/relay or some kind of filters to ensure
one does not get into the other. And even though we're talking VHF and
UHF, good filers which will provide the separation you need yet not
degrade the signal you want are expensive. If you're only talking one
frequency, maybe a couple of sets of duplexers will work - one set for
each band.

Of course, rf detecting coax switches will work - but you also then need
to ensure that both don't try to transmit at the same time - one or both
will be transmitting into an open circuit (depending on how you wire
them up).

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

Jerry

I am going to declare myself lost on this one so please be patient. I had though I had addressed these issues when I said I was using a DCI Dual Band Filter and Diplexer. Is the DCI combination filter and diplexer insufficient to protect the two radios from each other? DCI claimed it would be. The model number is DCI-146-444-DX-DB. The web sight were it is listed is
http://www.dci.ca/?Section=Products&SubSection=Amateur. If I need to add Duplexers it is practical to do because the mobile ones available used are manageable money. If there is a real chance for damage in the event of simultaneous transmission then I will need to add circulators and dummy loads to the output of both radios. That will end up being a little pricy.

--
Tom Horne W3TDH

In article ,
Tom W3TDH wrote:

Thank you for the second tribander idea. I do not now have a 220 MHz
base antenna. So using a tribander instead of a dual band antenna will
add that additional bands worth of capability to me base station. Since
I am very heavily involved in local EMCOMM preparation that is a very
worthwhile thing to do. It must be a good day because I learned
something new.

My home base-station antenna is a Comet CX-333 (2m/220/440), with a
triplexer in the shack (Kenwood TS-2000 for 2m and 440, and a Kenwood
I-forget-what for 220). It seems to work very much as one would
expect. No complaints at all.

"Tom W3TDH" wrote in message
...
I am going to declare myself lost on this one so please be patient. I had
though I had addressed these issues when I said I was using a DCI Dual
Band Filter and Diplexer. Is the DCI combination filter and diplexer
insufficient to protect the two radios from each other? DCI claimed it
would be. The model number is DCI-146-444-DX-DB. The web sight were it
is listed is
http://www.dci.ca/?Section=Products&SubSection=Amateur. If I need to add
Duplexers it is practical to do because the mobile ones available used are
manageable money. If there is a real chance for damage in the event .of
simultaneous transmission then I will need to add circulators and dummy
loads to the output of both radios. That will end up being a little
pricy.


That DCI should be plenty to protect the two rigs. You may have a desense
on the 440 receiver if it on a near 3 rd harmonic of the 144 transmiter. It
won't be enough to cause any damage, just enough to block the 440 receiver.

On 3/12/2015 2:06 PM, Tom W3TDH wrote:
On Wednesday, March 11, 2015 at 8:15:54 PM UTC-4, Jerry Stuckle wrote:
On 3/11/2015 6:02 PM, Tom W3TDH wrote:
I am looking for recommendations for a dual band antenna that will serve two separate radios. The reason that I want to use a single antenna is that I have a limited number of mounting points for antennas. At present it will be hard for SWMBO; as in Rumpole's spouse, She Who Must Be Obeyed; to tolerate the use of both our home's gable ends and the chimney being used to support antennas. I am planning to replace my Diamond X-30 with a triband vertical for Six, Two, and .7 Meters. The chimney will then support a rotor aimed Two and .7 Meter beam. The second gable end will support the Two meter / Seventy Centimeter dual band vertical that I am asking for help in selecting.

One radio will be a two meter packet node which will be used as a Winlink Radio Message Server. The other radio will be a UHF D-STAR hotspot. I am willing to pay what is needed to to get the best antenna for this application but I don't want to waste money ineffectively. So the two meter radio will be in the 144 MHz portion of the band and I don't yet actually know were the D-STAR hotspot will be run. I have a DCI filter and diplexer to keep the two radios from actually knowing of each others existence. Since a hotspot is not supposed to be a terribly wide area installation I would imagine that I do not want an extremely high gain antenna but I am perfectly open to be reeducated on that. The difficulty is that I would guess that the Radio Message Server / Packet would benefit from as much horizontal gain as can be achieved. I have a home brewed collinear two meter J-Pole that has been a good performer on two meters and presents a low SWR on 440 MHz. I have yet to master
an
tenna modeling but I would imagine; given all the warnings I have read on line; that it has poor radiation pattern on UHF. Is it likely to be too poor a performer for a hot spot on UHF?

I really am asking because I want to know. I am not looking for encouragement to do something that will be ineffective. Thank you in advance for any help you may be willing to offer.

--
Tom Horne W3TDH


Tom,

There are a number of good antennas around. The problem is not going to
be the antenna, though - it will be separating the two radios. If you
transmit on one while both are connected to the antenna, you'll blow the
front end of the other.

You'll need either a coax switch/relay or some kind of filters to ensure
one does not get into the other. And even though we're talking VHF and
UHF, good filers which will provide the separation you need yet not
degrade the signal you want are expensive. If you're only talking one
frequency, maybe a couple of sets of duplexers will work - one set for
each band.

Of course, rf detecting coax switches will work - but you also then need
to ensure that both don't try to transmit at the same time - one or both
will be transmitting into an open circuit (depending on how you wire
them up).


Jerry

I am going to declare myself lost on this one so please be patient. I had though I had addressed these issues when I said I was using a DCI Dual Band Filter and Diplexer. Is the DCI combination filter and diplexer insufficient to protect the two radios from each other? DCI claimed it would be. The model number is DCI-146-444-DX-DB. The web sight were it is listed is
http://www.dci.ca/?Section=Products&SubSection=Amateur. If I need to add Duplexers it is practical to do because the mobile ones available used are manageable money. If there is a real chance for damage in the event of simultaneous transmission then I will need to add circulators and dummy loads to the output of both radios. That will end up being a little pricy.

--
Tom Horne W3TDH


Tom,

You said you were using a diplexer, but didn't specify which one. Many
of the cheap ones are OK for receive, but can't handle any significant
amount of transmit power. The DCI will handle 200 watts, so unless
you're planning on exceeding that, you should be OK. It's loss
specifications are pretty reasonable, also.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================