Re: International crystal manufacturing
Or you can use a crystal heater like I suggested earlier and use
their crystal.
Chuck
WB2EDV
On 11/21/2022 3:44 AM, Karl Shoemaker
wrote:
toggle quoted message
Show quoted text
It's Monday morning, November 21,? about 12:30am and my outgoing
line (Voip circuit) would not work so I had to use my in coming
line (regular POTS) landline expecting an expensive call on my
next billing.
The call went through using the keystrokes Doug gave.
I asked the person on the phone if they can change frequency on a
channel element, for example Motorola. He said they can not do
that.? They only make and sell the crystal itself.
So, I'm back to "square one".
--
-
Regards, Karl Shoemaker
To contact me, please visit SRG's web site at?
for the current email address.
|
Re: International crystal manufacturing
It's Monday morning, November 21,? about 12:30am and my outgoing line (Voip circuit) would not work so I had to use my in coming line (regular POTS) landline expecting an expensive call on my next billing.
The call went through using the keystrokes Doug gave.
I asked the person on the phone if they can change frequency on a channel element, for example Motorola. He said they can not do that.? They only make and sell the crystal itself.
So, I'm back to "square one".
--
-
Regards, Karl Shoemaker
To contact me, please visit SRG's web site at?
for the current email address.
|
Re: Circularly-polarized antennas for two-way?
Comprod looks interesting but can it be stacked in bays? Plus the cost is likely high for the average ham... I would think you could get a tubing bender and make your own for a heck of a lot less.
Many years ago when I was involved with an ATV repeater in Beaumont Texas we built a CP antenna similar to a Skew Planer ... In fact we supplied one to the Johnson Space Center amateur radio club for an ATV experiment off the shuttle in the mid-80s.. KE5O and I are the only two non NASA employees to be members of W5RRR because of that... Didn't hurt that another amateur friend of ours, Jerry Coles and I can't remember Jerry's call off the top of my head right now, was an engineer at NASA and flew a modified IFR 7550 on board the shuttle at our suggestion.. Jerry later worked for IFR and was instrumental in getting the 1600 working when the production line couldn't..
Ahh the fun days ?
I actually kicked around the idea about building a bat wing for 420 ATV.. or a traveling helix which I saw at KTVT 11 in Dallas in 96...it's described in Vol II or III of the Antenna Handbook by Yo and Lee.. The one at Channel 11 DFW was actually hand built by local consultant engineer William JB Smith..
CWB
On Sun, Nov 20, 2022, 8:39 PM Matt Wagner < mwaggy@...> wrote: I like RFI-EMI-GUY's recommendation of setting up a pair of receivers fed into a voter -- although building a CP antenna and setting up a receive voter is _two_ projects in one...
From what I've seen, Comprod makes a circularly polarized antenna, the 205-70, but doesn't really hype it any:
by VE3BYT and VE3KL describes the Skew-Planer antenna, which looks a lot like the cloverleaf antenna seen in 5.8 GHz drones and such. They note difficulty stacking them with anything metallic; it's unclear if this is a unique challenge with this design, though.
I think being able to stack a few of them in an array would be helpful, especially since a singular one effectively has -3 dB gain. Could be a fun little antenna project.
Neil you're not the only one! I've tried getting some information from the manufacturers on CPs and got almost nothing. I do know however that a North Texas group took a DB420 and rotated the dipole elements 90¡ã to horizontal with each pair out of phase at 180¡ã. This meant one dipole on the left was rotated 90¡ã over while the other dipole on the other side was rotated 90¡ã toward the viewer.? All bays were done this way...A pattern check showed an almost perfect horizontal pattern. DB would not acknowledge it because it was modification of their design and they had no intent on trying to prove it one way or the other. If you need more info you could email me direct
Chris WB5ITT?
?As a Broadcaster, I have asked many of the Commercial? Antenna? manufacturers? If? their Engineers? could develop a prototype antenna for me.? ZERO takers. ?? what I am looking for is a Vertically mounted? Horizontally Polarized? antenna? with at least 9-19 db gain? around 426-440 Mhz? spectrum? for an ATV? repeater ? Yeas? ago? I built a loop ring open Alford slot cage antenna. It worked ok.? Lost the design plans? in a house fire.?? have not been able to Find them since.?? But? looking for a Pipe style? Slotted Dipole array. ? Anyone? have? any? Knowledge? on designing these with specs?? for 426-440??
? Neal? KA2CAF ?not sure if there is still an ATV? repeater ? located at Brookdale? Community College? in NJ? on the WBJB? FM? Tower. ?still have My ATV? gear? , and want to Tinker.
On Sunday, November 20, 2022 at 06:33:13 PM EST, Chris Boone < setxtelecom@...> wrote:
Circular polarization eliminates a lot of mobile flutter due to reflections. Radio broadcast industry normally uses right hand circular polarization on FM and left hand circular polarization on the HD signals. Television is now leaning more toward elliptical with 70% in the horizontal and 30% in the vertical. If I recall the test that was mentioned in the earlier email was written up in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP array that was built used two Cushcraft four poles mounted at 45¡ã off of vertical in each direction. Basically a 4 bay turnstile turned on its side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is real easy to duplicate and works rather well. On 2 meters it would be even easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73 John, kx4o? On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote: Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff. But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Re: Series-mode surge protection
I am not familiar with the product you mention.? Evaluate what is used to clamp the voltage?? Is the device UL1449 Edition 3 or 4 listed?? What is the let through voltage?? An on line search did not provide any of this information.? I suggest avoiding any product that is not UL1449 Ed 3 or 4 listed.? And, you desire a product that has a minimal let through voltage when tested to the UL specifications.? That should be listed on the product literature.? You desire something around 600 volts for a 120 volt circuit.? Avoid any product that is not UL listed and does not offer the let through voltage rating.? Review the Motorola R56 Standards referenced above for suitable specifications.? You desire something that meets those specifications or at a bare minimum is UL1449 Ed 3 or 4 listed with a clamping voltage around 600 V for a 120 V circuit.? For an in line or sup-panel device you desire line to line, line to neutral, neutral to ground and line to ground protection.? No concern about neutral to ground protection at the main panel as those conductors are required to be bonded together at the main disconnecting device where you would install your first device.? Series inductance is a plus but you still must have something to limit the spikes/surges to a safe level.? And, you want a safe device therefore the UL listing.? Good surge protection practices are to offer a suitable unit at the main panel, another at the sub panel if there is one and a device at the load to be protected.? Suitable protection is not as simple as installing a device at the load you desire to protect.? For reasonable protection you desire a Type 1 or 2 device on the main panel, a type 2 device on any sub-panel and a type 3 device at the load to be protected.? For devices installed at the panel the conductors must be routed as straight and be as short as possible. Typically an over current protective device is required at the panel.? It is very important to follow the manufacturers installation instructions.? 73? W3YVV
|
Re: Circularly-polarized antennas for two-way?
I like RFI-EMI-GUY's recommendation of setting up a pair of receivers fed into a voter -- although building a CP antenna and setting up a receive voter is _two_ projects in one...
From what I've seen, Comprod makes a circularly polarized antenna, the 205-70, but doesn't really hype it any:
by VE3BYT and VE3KL describes the Skew-Planer antenna, which looks a lot like the cloverleaf antenna seen in 5.8 GHz drones and such. They note difficulty stacking them with anything metallic; it's unclear if this is a unique challenge with this design, though.
I think being able to stack a few of them in an array would be helpful, especially since a singular one effectively has -3 dB gain. Could be a fun little antenna project.
Neil you're not the only one! I've tried getting some information from the manufacturers on CPs and got almost nothing. I do know however that a North Texas group took a DB420 and rotated the dipole elements 90¡ã to horizontal with each pair out of phase at 180¡ã. This meant one dipole on the left was rotated 90¡ã over while the other dipole on the other side was rotated 90¡ã toward the viewer.? All bays were done this way...A pattern check showed an almost perfect horizontal pattern. DB would not acknowledge it because it was modification of their design and they had no intent on trying to prove it one way or the other. If you need more info you could email me direct
Chris WB5ITT?
?As a Broadcaster, I have asked many of the Commercial? Antenna? manufacturers? If? their Engineers? could develop a prototype antenna for me.? ZERO takers. ?? what I am looking for is a Vertically mounted? Horizontally Polarized? antenna? with at least 9-19 db gain? around 426-440 Mhz? spectrum? for an ATV? repeater ? Yeas? ago? I built a loop ring open Alford slot cage antenna. It worked ok.? Lost the design plans? in a house fire.?? have not been able to Find them since.?? But? looking for a Pipe style? Slotted Dipole array. ? Anyone? have? any? Knowledge? on designing these with specs?? for 426-440??
? Neal? KA2CAF ?not sure if there is still an ATV? repeater ? located at Brookdale? Community College? in NJ? on the WBJB? FM? Tower. ?still have My ATV? gear? , and want to Tinker.
On Sunday, November 20, 2022 at 06:33:13 PM EST, Chris Boone < setxtelecom@...> wrote:
Circular polarization eliminates a lot of mobile flutter due to reflections. Radio broadcast industry normally uses right hand circular polarization on FM and left hand circular polarization on the HD signals. Television is now leaning more toward elliptical with 70% in the horizontal and 30% in the vertical. If I recall the test that was mentioned in the earlier email was written up in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP array that was built used two Cushcraft four poles mounted at 45¡ã off of vertical in each direction. Basically a 4 bay turnstile turned on its side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is real easy to duplicate and works rather well. On 2 meters it would be even easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73 John, kx4o? On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote: Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff. But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Re: Circularly-polarized antennas for two-way?
I heard, quite a few decades ago, that some who worked at Jampro (broadcast Fm antenna manufacturer) in California, had a scaled back model of one of the FM CP antennas for CP, on 220 MHz. I've always thought about someplace like NYC should try a CP antenna due to the concrete canyons and multipath. Anyone else hear about the Jampro on 220?
Tom K8TB
|
Re: Circularly-polarized antennas for two-way?
I made a CP (helix) antenna for analog 800MHz cellular.? This was in the early 1990s, when the part 22 cell rules required TX to be vertically polarized so I didn't mess with the TX antenna. I did this in an urban environment.? I had an automated measurement setup make 10 receive signal strength measurements per second on the vertical and also on the CP antenna when that channel was active.? The peak signal strengths were similar, but the average signal strength was higher on the CP antenna. Measuring receive signal strength on two vertical antennas 10 feet apart, and doing diversity "combining", was a couple of dB better than one CP antenna. I suppose I should have tried two helix RX antennas, but rhe company picked up two more markets and I got too busy to continue with the experiments. Eric
WB6TIX
|
Re: Circularly-polarized antennas for two-way?
Neil you're not the only one! I've tried getting some information from the manufacturers on CPs and got almost nothing. I do know however that a North Texas group took a DB420 and rotated the dipole elements 90¡ã to horizontal with each pair out of phase at 180¡ã. This meant one dipole on the left was rotated 90¡ã over while the other dipole on the other side was rotated 90¡ã toward the viewer.? All bays were done this way...A pattern check showed an almost perfect horizontal pattern. DB would not acknowledge it because it was modification of their design and they had no intent on trying to prove it one way or the other. If you need more info you could email me direct
Chris WB5ITT?
?As a Broadcaster, I have asked many of the Commercial? Antenna? manufacturers? If? their Engineers? could develop a prototype antenna for me.? ZERO takers. ?? what I am looking for is a Vertically mounted? Horizontally Polarized? antenna? with at least 9-19 db gain? around 426-440 Mhz? spectrum? for an ATV? repeater ? Yeas? ago? I built a loop ring open Alford slot cage antenna. It worked ok.? Lost the design plans? in a house fire.?? have not been able to Find them since.?? But? looking for a Pipe style? Slotted Dipole array. ? Anyone? have? any? Knowledge? on designing these with specs?? for 426-440??
? Neal? KA2CAF ?not sure if there is still an ATV? repeater ? located at Brookdale? Community College? in NJ? on the WBJB? FM? Tower. ?still have My ATV? gear? , and want to Tinker.
On Sunday, November 20, 2022 at 06:33:13 PM EST, Chris Boone < setxtelecom@...> wrote:
Circular polarization eliminates a lot of mobile flutter due to reflections. Radio broadcast industry normally uses right hand circular polarization on FM and left hand circular polarization on the HD signals. Television is now leaning more toward elliptical with 70% in the horizontal and 30% in the vertical. If I recall the test that was mentioned in the earlier email was written up in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP array that was built used two Cushcraft four poles mounted at 45¡ã off of vertical in each direction. Basically a 4 bay turnstile turned on its side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is real easy to duplicate and works rather well. On 2 meters it would be even easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73 John, kx4o? On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote: Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff. But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Re: Circularly-polarized antennas for two-way?
ive actually built and tested cp antennas for fm broadcast with great results when stacked. i completely agree why no one will build a 2 meter or 440 version. that being said....im either going to re-visit this and try to calculate the dimensions...unless someone
super smarter than me can whip one up in a program and give me the dimensions and ill build it. ill post pics of the fm broadcast prototype i built(copied) later.
jonny? kf6phx
toggle quoted message
Show quoted text
?As a Broadcaster, I have asked many of the Commercial? Antenna? manufacturers? If? their Engineers? could develop a prototype antenna for me.? ZERO takers.
?? what I am looking for is a Vertically mounted? Horizontally Polarized? antenna? with at least 9-19 db gain? around 426-440 Mhz? spectrum? for an ATV? repeater
? Yeas? ago? I built a loop ring open Alford slot cage antenna. It worked ok.? Lost the design plans? in a house fire.?? have not been able to Find them since.?? But? looking for a Pipe style? Slotted Dipole array.
? Anyone? have? any? Knowledge? on designing these with specs?? for 426-440??
? Neal? KA2CAF
?not sure if there is still an ATV? repeater ? located at Brookdale? Community College? in NJ? on the WBJB? FM? Tower.
?still have My ATV? gear? , and want to Tinker.
On Sunday, November 20, 2022 at 06:33:13 PM EST, Chris Boone <setxtelecom@...> wrote:
Circular polarization eliminates a lot of mobile flutter due to reflections. Radio broadcast industry normally uses right hand circular polarization on FM and left hand circular polarization on the HD signals. Television is now leaning more toward elliptical
with 70% in the horizontal and 30% in the vertical.
If I recall the test that was mentioned in the earlier email was written up in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP array that was built used two Cushcraft four poles mounted at 45¡ã off of vertical in each direction.
Basically a 4 bay turnstile turned on its side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is real easy to duplicate and works rather well. On 2 meters it would be even easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what
the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73
John, kx4o?
On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote:
Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff.
But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with?
It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Re: Circularly-polarized antennas for two-way?
?
I've always wanted to get a circular polarized
antenna to try satellite work.? Long ago back in the 70s, a friend who
built a two meter repeater and I did a lot of experimenting? I was his weak
signal generater when needed.?I was about 55 miles away.? We?also
did a bit of playing horizontal versis vertical polarization.? We didn't
have circular stuff.? First thing we found was that two meters could go
into some very deep fades, lasting 4 or 5 minutes.? We found that vertical
polarity was often a bit stronger on peaks, but the horizontal antennas were
more consistent, not quite as strong, but didn't fade out quite
so?much.?
?
----- Original Message -----
Sent: Sunday, November 20, 2022 5:10 PM
Subject: Re: [repeater-builder] Circularly-polarized antennas for
two-way?
?As a Broadcaster, I have asked many of
the Commercial? Antenna? manufacturers? If? their
Engineers? could develop a prototype antenna for me.? ZERO
takers.
?? what I am looking for is a
Vertically mounted? Horizontally Polarized? antenna? with at
least 9-19 db gain? around 426-440 Mhz? spectrum? for an
ATV? repeater
? Yeas? ago? I built a loop ring
open Alford slot cage antenna. It worked ok.? Lost the design plans?
in a house fire.?? have not been able to Find them since.??
But? looking for a Pipe style? Slotted Dipole array.
? Anyone? have? any?
Knowledge? on designing these with specs?? for 426-440??
? Neal? KA2CAF
?not sure if there is still an ATV?
repeater ? located at Brookdale? Community College? in NJ?
on the WBJB? FM? Tower.
?still have My ATV? gear? , and
want to Tinker.
On Sunday, November 20, 2022 at 06:33:13 PM EST, Chris Boone
<setxtelecom@...> wrote:
Circular polarization eliminates a lot of mobile flutter due to
reflections. Radio broadcast industry normally uses right hand circular
polarization on FM and left hand circular polarization on the HD signals.
Television is now leaning more toward elliptical with 70% in the horizontal and
30% in the vertical.
If I recall the test that was mentioned in the earlier email was written up
in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP
array that was built used two Cushcraft four poles mounted at 45¡ã off of
vertical in each direction. Basically a 4 bay turnstile turned on its
side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is
real easy to duplicate and works rather well. On 2 meters it would be even
easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient
documentation out there showcasing some experiment?where a linear and
circular antenna at a repeater site were choosable by the users (via DTMF) I
guess to get a consensus?which one offered?what the users'
observed?as "mo better."? Apparently?the CP won the
election.
It's said even with vertical mobile antennas, the randomness of
reflections of things can cause fluttering and such and CP on the mountain top
alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in
Virginia in the upcoming year... so I am.? Stay tuned.
73
John, kx4o?
On Sun, Nov 20, 2022 at 5:48 PM
Matt Wagner < mwaggy@...> wrote:
Howdy,
I went down a little bit of a rabbit hole reading about the use of
circular polarity in antennas. I'm curious if anyone's experimented with it
for repeaters or traditional two-way stuff.
But, while I can read lots of theory about circular polarity in
antennas, and see people using it for various purposes, I've found
absolutely nothing about people running it on traditional two-way systems.
Is this something people have played around with? It sounds like it could be
useful, but I can't possibly be the first to have thought of this, so I
wonder if it ends up not working out well?
|
Re: Circularly-polarized antennas for two-way?
?As a Broadcaster, I have asked many of the Commercial? Antenna? manufacturers? If? their Engineers? could develop a prototype antenna for me.? ZERO takers. ?? what I am looking for is a Vertically mounted? Horizontally Polarized? antenna? with at least 9-19 db gain? around 426-440 Mhz? spectrum? for an ATV? repeater ? Yeas? ago? I built a loop ring open Alford slot cage antenna. It worked ok.? Lost the design plans? in a house fire.?? have not been able to Find them since.?? But? looking for a Pipe style? Slotted Dipole array. ? Anyone? have? any? Knowledge? on designing these with specs?? for 426-440??
? Neal? KA2CAF ?not sure if there is still an ATV? repeater ? located at Brookdale? Community College? in NJ? on the WBJB? FM? Tower. ?still have My ATV? gear? , and want to Tinker.
On Sunday, November 20, 2022 at 06:33:13 PM EST, Chris Boone <setxtelecom@...> wrote:
Circular polarization eliminates a lot of mobile flutter due to reflections. Radio broadcast industry normally uses right hand circular polarization on FM and left hand circular polarization on the HD signals. Television is now leaning more toward elliptical with 70% in the horizontal and 30% in the vertical. If I recall the test that was mentioned in the earlier email was written up in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP array that was built used two Cushcraft four poles mounted at 45¡ã off of vertical in each direction. Basically a 4 bay turnstile turned on its side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is real easy to duplicate and works rather well. On 2 meters it would be even easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73 John, kx4o? On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote: Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff. But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Re: Circularly-polarized antennas for two-way?
Circular polarization eliminates a lot of mobile flutter due to reflections. Radio broadcast industry normally uses right hand circular polarization on FM and left hand circular polarization on the HD signals. Television is now leaning more toward elliptical with 70% in the horizontal and 30% in the vertical. If I recall the test that was mentioned in the earlier email was written up in Bill Pasternak's "All you wanted to know about FM and repeaters" book. The CP array that was built used two Cushcraft four poles mounted at 45¡ã off of vertical in each direction. Basically a 4 bay turnstile turned on its side.
I thought about building a CP for 6m. The Nicom series in FM broadcast is real easy to duplicate and works rather well. On 2 meters it would be even easier since the size would be smaller.
Chris WB5ITT?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73 John, kx4o? On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote: Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff. But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Re: Circularly-polarized antennas for two-way?
I believe there was some research using both horizontal and
vertical polarity with pagers back in pager days.
I think it was Bogner that made the antennas for 900 Mhz. Pagers
are seldom vertical or horizontal. The test were in deep urban
areas. What I remember about the results was about a 3dB
improvement in receiving pages.
They decided that down tilt was more effective for a lower cost.
On 11/20/2022 5:12 PM, John Huggins
wrote:
toggle quoted message
Show quoted text
I've gone down this rabbit hole as well.? There's some
ancient documentation out there showcasing some
experiment?where a linear and circular antenna at a repeater
site were choosable by the users (via DTMF) I guess to get a
consensus?which one offered?what the users' observed?as "mo
better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the
randomness of reflections of things can cause fluttering and
such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test
exactly this here in Virginia in the upcoming year... so I
am.? Stay tuned.
73
John, kx4o?
On Sun, Nov 20, 2022 at 5:48
PM Matt Wagner < mwaggy@...>
wrote:
Howdy,
I went down a little bit of a rabbit hole reading
about the use of circular polarity in antennas. I'm
curious if anyone's experimented with it for repeaters
or traditional two-way stuff.
But, while I can read lots of theory about circular
polarity in antennas, and see people using it for
various purposes, I've found absolutely nothing about
people running it on traditional two-way systems. Is
this something people have played around with? It sounds
like it could be useful, but I can't possibly be the
first to have thought of this, so I wonder if it ends up
not working out well?
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Re: Circularly-polarized antennas for two-way?
If you are considering CP for a repeater station I would suggest diversity reception using as a second antenna a horizontal loop. Use two identical receivers and a voting comparitor.?
--
The Real RFI-EMI-GUY
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Re: Circularly-polarized antennas for two-way?
I've gone down this rabbit hole as well.? There's some ancient documentation out there showcasing some experiment?where a linear and circular antenna at a repeater site were choosable by the users (via DTMF) I guess to get a consensus?which one offered?what the users' observed?as "mo better."? Apparently?the CP won the election.
It's said even with vertical mobile antennas, the randomness of reflections of things can cause fluttering and such and CP on the mountain top alleges to help with this.
All this in mind, I'm actually in a position to test exactly this here in Virginia in the upcoming year... so I am.? Stay tuned.
73 John, kx4o?
On Sun, Nov 20, 2022 at 5:48 PM Matt Wagner < mwaggy@...> wrote: Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff. But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
|
Circularly-polarized antennas for two-way?
Howdy,
I went down a little bit of a rabbit hole reading about the use of circular polarity in antennas. I'm curious if anyone's experimented with it for repeaters or traditional two-way stuff.
Of particular interest to me is using it only on one end. A lot of satellite comms use circular polarity on both ends, and can get fairly good isolation between right-handed and left-handed circular polarity. But, as I understand it, a lot of broadcast FM uses circularly polarized antennas to listeners with linearly polarized antennas, because there's a blend of vertical and horizontal antennas out there, not to mention the 45-degree pattern seen on some cars now.
From what I've read, about 3 dB is lost when a circularly polarized signal is received by a linear antenna. But what's gained is that the antenna orientation doesn't matter, and you avoid potentially 20-30 dB loss to an antenna in the wrong orientation. (Broadcasters can work around this by stacking a number of FM bays like we do with folded dipole arrays.)
I also read a tiny bit about some experiments on HF, on the theory that multipath fading would be reduced significantly.
It would seem to me that doing something similar on a repeater antenna could be beneficial, especially if you're serving users on portables. The signal strength for a ham repeater I'm listening to in the background is bouncing around by more than 10 dB right now; I suspect part of it is the fiberglass whip on top of a hill flexing a bit with the 30mph wind gusts we're having. I've also found that with somewhat weak signals being heard on an HT, sometimes the signal is greatly improved by tilting the radio in some particular direction, maybe due to various reflections and obstructions along the way.
But, while I can read lots of theory about circular polarity in antennas, and see people using it for various purposes, I've found absolutely nothing about people running it on traditional two-way systems. Is this something people have played around with? It sounds like it could be useful, but I can't possibly be the first to have thought of this, so I wonder if it ends up not working out well?
73, Matt, N1ZYY
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Re: Need documentation for SS-32M tone encoder
And then there's this one. Either I forgot or missed the documentation on RB. It's close to the SS-32SMP but not the same. I've got an email in for Randy.? It's been way long since I've been messing around with these for HTs.  -- - Regards, Karl Shoemaker To contact me, please visit SRG's web site at? for the current email address.
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MIII Programming Software
Group:
I¡¯m looking for the correct software to program a MIII ¡°racing stripe¡± model of GE radio.
I have programmed the older version (no stripes) in the past with these DOS programs:
?
Mastr III Shelf Program 15.0
Station Utility Program 9.00
Station Specials Editor 2.00 (not sure I have used this, or even if it is appropriate)
***
Will these program the racing stripe MIII, or will they brick it?
?
Is better software available for either version of the MIII¡¯s?
Dan K5FVL
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Re: Astro Spectra Consolette audio board
The closest I have is revision 'C'
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Re: GE MSTR 2 special (Factory Repeater?) FREE
That might be a UHF version of a GE AVR simplex repeater that connects to a regular mobile radio.
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Karl Shoemaker
Chris Boone WB5ITT
Matt Wagner
Don Clark
RFI-EMI-GUY