Re: R1225 Ribbon Cable set
There's a set of original cables here:
But the price is, in my opinion, OUTRAGEOUS.??
All they are is 1/10 inch spaced single row ribbon cable.
Mike
|
Re: MIII Programming Software
M III ver 17 was the last version we had also. The RPM software we got IS tied to computer by a key. The only way around we found was to clone the hard drives, which meant you had to have the same exact computers.
|
Re: Circularly-polarized antennas for two-way?
Will a voter switch fast/often enough to keep up with the flutter style fading?
Eric WB6TIX
On Mon, Nov 21, 2022, 09:00 RFI-EMI-GUY < rhyolite@...> wrote: Actually, My suggestion is for the second antenna to he a horizontal loop avoiding the hassle and loss related to a CP antenna.
On Sun, Nov 20, 2022 at 09:39 PM, Matt Wagner 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?
?
?
?
?
?
?
--
The Real RFI-EMI-GUY
|
Re: MIII Programming Software
The last version of the Mastr IIe/III program, which I believe is V17, is what is needed, and it is not tied to a PC. It looks DOS based, but it runs fine in XP at least.
ProGrammer is what is tied to a PC, and I never used it for MIII's. I don't even remember seeing the option for that to be supported.
toggle quoted message
Show quoted text
On 11/21/2022 11:38 AM, J Donovan via groups.io wrote: For the newer stations (stripes) you will need the newer win based software package that is tied to you computer. I don't know if Harris still supports these stations as we bought everytning we needed in 2012. It required an online verification or an activation key for each computer (seat)? by email.
Having said that and using both packages from my experience on stations we purchased in 2012 you can program the newer stations with the older DOS based software (PIA), but using the newer software on the older non striped version will brick them.
_._,_._,_
|
Re: MIII Programming Software
Having said that and using both packages from my experience on stations we purchased in 2012
you can program the newer stations with the older DOS based software (PIA), but using the newer
software on the older non striped version will brick them. That has been my experience as well, at least for analog stations. You may need the Windows software to program a P25 station which has a DSP card needed for P25; I don't have any P25 stations so that's just an educated guess... --- Jeff WN3A -- This email has been checked for viruses by Avast antivirus software. www.avast.com
|
Re: MIII Programming Software
For the newer stations (stripes) you will need the newer win based software package that is tied to you computer. I don't know if Harris still supports these stations as we bought everytning we needed in 2012. It required an online verification or an activation key for each computer (seat)? by email.
Having said that and using both packages from my experience on stations we purchased in 2012 you can program the newer stations with the older DOS based software (PIA), but using the newer software on the older non striped version will brick them.
|
Re: Circularly-polarized antennas for two-way?
Actually, My suggestion is for the second antenna to he a horizontal loop avoiding the hassle and loss related to a CP antenna.
toggle quoted message
Show quoted text
On Sun, Nov 20, 2022 at 09:39 PM, Matt Wagner 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?
?
?
?
?
?
? -- The Real RFI-EMI-GUY
|
I have excess to my needs a single port RLC Club in rack mount case.. bought it planning to add the deluxe II board but decided not to since I have already too many RLCs. Asking $550 for it plus shipping
Chris WB5ITT
|
Re: Series-mode surge protection
Here is a link to the SurgeX SX-1115-RT?datasheet:
According to the datasheet:
- The device is UL 1449 listed.
- The surge let-through voltage is zero volts.
This web page describes the theory of operation:
"...a reactor with two opposing air core inductors to slow surge current down to a trickle. Any residual energy leaving the inductors is eliminated by a clamping board. It removes all surge energy, allows zero let-through voltage to reach connected equipment, the ground or building wiring, and produces no common-mode disturbances. Its zero let-through technology stops all surge energy, up to 6,000 volts, without producing harmful ground contamination."
|
Re: International crystal manufacturing
Nobody ever said they were a full service shop like International was. They sell good stable crystals that you should be able to pop into a channel element and go. ?I have two low band crystals in a Micor base and am not having any problems. ?
You are not back to square one, you have a good resource for crystals l, now you just have to do the assembly work yourself. I am sure you will get better results and less frustration than products from Bomar despite paying out the rear end for international shipping by DHL. ?
As for the international calling issue, VOIP providers can do whatever they want because they are largely unregulated and don¡¯t have to follow the dialing plan mandated by the state PUC. They try to follow the NANP but due to their revenue constraints they are not going to use a real carrier to get around the world. They stick with other SIPP providers and, as a result, you get what you pay for. ?
As for the ¡°dial a code to make a long distance call on a party line to get the billing right¡± that code was called a ¡°circle digit¡±. ?I have never seen it used in practice but see the references in the software for line assignment. ?Only have seen single digit circle digits, never two digit circle digits because party lines never went beyond eight parties so one digit was enough. Otherwise the call went ONI for Operator Number Identification.?
Okay back to crystals¡
Kevin KA0JQO?
|
Re: Two UHF repeaters sharing the same antenna.
I did lol? we're going to try to go back up to the side again over the Thanksgiving holidays hopefully we can get this thing back up online and working. Frequency on the ham band is 444.050 plus offset
And the commercial band is 462.275 plus offset.
I have two other old station Masters down in the shop. One of these I'm going to use to replace the broken one up on the tower.
I'm sure you knew what I meant... 500 KHz between TX frequencies
(not MHz).
Jim W7RY
On 11/21/2022 7:33 AM, Keith Ford
wrote:
Thanks Jim for the reply yeah I have to Motorola
Micor and a Motorola quantar they have the same setup as you're
talking about but one of them is a six cavitity T1500 and the
other a six cavity which should supply even more isolation
between the two.
Yes.
Motorola UHF community repeaters were done this way for
years configured the following way:
- 500 KHz or more spacing
between transmit frequencies
- 4 cavity Bandpass duplexers on each repeater
- DUAL circulator/isolator on the output of each
transmitter between the duplexer and transmitter
- Proper cable lengths between the output of each
duplexer to the common shared antenna
Worked great with minimal losses and no desensce. If you
look at the spec sheet for the T1500 series of duplexer,
you may find the cable information in that document for
doing just this. A UHF 50 ohm antenna combiner/splitter
would do the same thing of combining the outputs of each
duplexer.
73, Jim W7RY
On 11/16/2022 9:11 AM, Keith Ford wrote:
can I put two UHF repeaters on the same
antenna by putting some filtering in between them one is
in business band and the other one is amateur radio
band. Just reaching out there in a group has anybody
ever done this before I've got one antenna that is
damaged it appears to have water in it and the SWR is
high.
thanks.
KF4RGR? ? ? ?Keith Ford
--
Thanks and 73, Jim W7RY
--
Thanks and 73, Jim W7RY
|
Re: Two UHF repeaters sharing the same antenna.
I'm sure you knew what I meant... 500 KHz between TX frequencies
(not MHz).
Jim W7RY
On 11/21/2022 7:33 AM, Keith Ford
wrote:
Thanks Jim for the reply yeah I have to Motorola
Micor and a Motorola quantar they have the same setup as you're
talking about but one of them is a six cavitity T1500 and the
other a six cavity which should supply even more isolation
between the two.
Yes.
Motorola UHF community repeaters were done this way for
years configured the following way:
- 500 KHz or more spacing
between transmit frequencies
- 4 cavity Bandpass duplexers on each repeater
- DUAL circulator/isolator on the output of each
transmitter between the duplexer and transmitter
- Proper cable lengths between the output of each
duplexer to the common shared antenna
Worked great with minimal losses and no desensce. If you
look at the spec sheet for the T1500 series of duplexer,
you may find the cable information in that document for
doing just this. A UHF 50 ohm antenna combiner/splitter
would do the same thing of combining the outputs of each
duplexer.
73, Jim W7RY
On 11/16/2022 9:11 AM, Keith Ford wrote:
can I put two UHF repeaters on the same
antenna by putting some filtering in between them one is
in business band and the other one is amateur radio
band. Just reaching out there in a group has anybody
ever done this before I've got one antenna that is
damaged it appears to have water in it and the SWR is
high.
thanks.
KF4RGR? ? ? ?Keith Ford
--
Thanks and 73, Jim W7RY
--
Thanks and 73, Jim W7RY
|
Re: Two UHF repeaters sharing the same antenna.
Thanks Jim for the reply yeah I have to Motorola Micor and a Motorola quantar they have the same setup as you're talking about but one of them is a six cavitity T1500 and the other a six cavity which should supply even more isolation between the two.
Yes.
Motorola UHF community repeaters were done this way for years
configured the following way:
- 500 MHz or more spacing between transmit frequencies
- 4 cavity Bandpass duplexers on each repeater
- DUAL circulator/isolator on the output of each transmitter
between the duplexer and transmitter
- Proper cable lengths between the output of each duplexer to
the common shared antenna
Worked great with minimal losses and no desensce. If you look at
the spec sheet for the T1500 series of duplexer, you may find the
cable information in that document for doing just this. A UHF 50
ohm antenna combiner/splitter would do the same thing of combining
the outputs of each duplexer.
73, Jim W7RY
On 11/16/2022 9:11 AM, Keith Ford
wrote:
can I put two UHF repeaters on the same antenna by
putting some filtering in between them one is in business band
and the other one is amateur radio band. Just reaching out there
in a group has anybody ever done this before I've got one
antenna that is damaged it appears to have water in it and the
SWR is high.
thanks.
KF4RGR? ? ? ?Keith Ford
--
Thanks and 73, Jim W7RY
|
Re: International crystal manufacturing
Their modular oscillator units have great temp stability specs, so we tried to order the one that puts out a modified sine wave, but was told something like 100 would be doable, but not just a few.
John W1GPO
On 11/21/2022 3:44 AM Karl Shoemaker <srg734@...> wrote:
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
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?
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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
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RFI-EMI-GUY
Chris Boone WB5ITT
Karl Shoemaker
Matt Wagner