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Hi Dan,

On Mon, Nov 21, 2022 at 09:58 AM, Burt K6OQK wrote:

Matt,

I used a circularly polarized antenna on the WA6TDD repeater back in the 70's and early 80's. The antenna was a single bay antenna made specifically for the repeater by the JAMPRO antenna Company as a test for the 2-way world. It even has de-icers!? If you're familiar with the JAMPRO Penetrator antenna, this was the same antenna with the exception that it was center mounted; the mast was straight down below the white insulator at the feed point. This replaced a (linear) Phelps Dodge 4.8 dB gain Super-Duper Storm Master antenna.? The gain went from approximately +4.8 db to - 3 dB.? The ERP went from 100 watts to approximately 13 watts. Just to clarify, the repeater transmit was now circular and all of the users were linear; none of the users were circular.?

The difference in coverage of transmit was amazing. For example: at the time I worked in a 33 story building with 6 levels of underground parking. With the linear antenna I was able to copy the repeater with its 100 watts ERP about 25 feet into the parking entrance and that was it. With the circular antenna on the repeater and a 19" spike on the top of my car I was able to copy the repeater solid down to the 2nd level and hear it spotty down to the 5th level.? At some places on the 5th level I could find spots that were almost full quieting.? People that listened to the repeater with radios like the old Patrolmen type receivers claimed that they no longer had to place their receivers near the window and fiddle with the antenna, they could now take the radio anywhere in their homes and hear the repeater with no problems. It was solid through areas like the Santa Ana Canyon and Sepulveda Pass.

I was one of those users back then. ?

And for those totally unfamiliar with Los Angeles geography (probably 99% of the readers) the attached JPG will provide some context.? The repeater on Mt Wilson is in the upper right of the image, Sepulveda Pass is my sloppy red line, it's on the left side and about 25 miles from the transmitter.? Burt's old work location with the 5-level deep underground parking garage is at the green circle and about 20 miles from the repeater.?? His mention of Sepulveda Pass is significant as to the performance of the Jampro antenna.?? The pass is about 6 to 7 miles (9.5 to 11.25 km) long, and the walls are from 200 to 1000 feet (60-300 m) tall depending on where you are in the pass.? The 405 freeway (4 lanes in each direction) is a major north-south traffic thoroughfare in the pass.? When the repeater was on the linear antenna it was hearable for about the first mile when going north or south. With the Jampro it was solid copy for the full length - the dead zone wasn't even there.

Nobody has discussed UHF yet.? Back in 2020 I talked to Dielectric about taking one of their CP antenna designs and special ordering it for ham band UHF.?? The nearest stock US frequency is channel 14 which is 470 to 476 MHz.? In the Los Angeles area (and many others) that's a commercial 2-way band, with 470-473 as repeater outputs and 473-476 as inputs.? I help maintain over 40 commercial repeaters in that range.

They were quite interested in making them.?? VHF as well.

They suggested this model....? Their words were: "this is the one you want":?? https://www.dielectric.com/antenna/dlp-low-power-antenna

Another page: https://www.dielectric.com/manuals/dlp-ib

As an alternate, they suggested this:?? Dielectric DCR (less expensive but single bay):?? https://www.dielectric.com/antenna/dcr-m-hdr-m

Several of the sites where I have commercial equipment have a 406-512 master receive antenna and a number of multiple cavity "window filters" feeding a mess
of repeater receivers at 440-445 (ham), 445-460 (commercial), 465-470 (ditto), 473-476 (ditto) and 508-511 (more of the same).??
The repeater transmitters are +5 MHz for ham, -5 MHz for 450 and 460 MHz, and -3 for 470 MHz.??
Multiple repeater transmitters are combined (as many as five) to a single transmit antenna.?? CP transmit antennas would be a benefit in this situation.

Dielectric pointed out that several models are designed to combine multiple TV transmitters and can be up to 60 MHz wide.

But the boss wouldn't spring for one...

Mike WA6ILQ

At 11/24/2022 09:53 PM, you wrote:

Whoever said SLA batteries do not leak was wrong. This is what I found when responding to a report of fluid leaking out of a UPS. Because the battery was swollen it took some convincing to get it out of the UPS. The inside of the UPS was wet and the battery was split open on both sides. My best guess is that the trickle charging circuit in the UPS failed and overcharged the battery until it burst. So much for the theory that sealed lead acid batteries won't leak.

I've seen stacks of bad APC UPS batteries at work. ALL of them were swollen.

APC UPS = battery cooker.

Bob NO6B

I have been reading this on ad off and decided to add my 2-cets
I am using both the new and older style GE voters for my 6M repeaters.
My experience has been the new black panel power supplies are less reliable than the older grey panel ones. Comparing the electrolytic filter caps to those used in the early supplies and one can see GE went to cheaper parts. This was discovered after a black panel supply started adding 120Hz hum to audio. The older (much older!) grey panel supply never had any hum.?
I replaced all electrolytics with fresh new 80C rated caps and they have been working well ever since.
Another gripe, removing a PS module is a PITA in these things, the line cord is hard wired and goes out the back so if you need to replace a PS you have to access the rear of the rack and fish the cord out as you pull the module. In some instances this can be a job. if they had used a plug/socket it would have been a lot better IMHO.? ?

I aso had one black face voter card fail. With its surface mounted components its basically trash now, no troubleshooting those things! Older grey panel cards have never faulted on me, maybe because they use pot cores.
There was a method of avoiding the problem with the older cards using incandescent lamps, because they send a fault when the lamps burn out. I think we added dropping resistors or used a higher voltage bulb but can't recall, this is one area the black panel cards are better with their LED's.? ?
As they say, YMMV so just be sure to replace the filter caps in the supplies, either new or old if you want to avoid a field trip eventually.
Despite all this, GE voters are great!? ?
Reid W6MTF

I contacted the OEM and got a quick reply. One of my questions is that they still are in business.? They had trouble obtaining certain parts in the past. I assume that's some special I.C.s.?? I would imagine the next version's engineering will take that into consideration. So far I'm impressed with what they have put out. I'll running over to that Group for further discussion.
--
-
Regards, Karl Shoemaker
To contact me, please visit SRG's web site at?
for the current email address.

Remember, too,that copper and alum are not very close on the Galvnic chart so use the proper interfacing "grease". Look up on line about galvinc (spelling?) corrosion.
Copper is more expensive however, most of the commercial and State remote mountain top sites go with that metal and not needing to "fix" such metal differences.
I found a copper ground buss at a fraction of the new price at a second-hand store.
All your line's outer shield will be copper anyway.?

On that other thread the transition points were not discussed, or from what I saw.? In this case you do want your runs to take sharp bends, hopefully 90°.
Lighting travels fast (LOL) and does not have nice "tires" to hold the corners so it flies off. Just have a "nice" landing place for all that voltage :)
RTFM.
--
-
Regards, Karl Shoemaker
To contact me, please visit SRG's web site at?
for the current email address.

So, Chris, I gather, the newer units can work without a ST as well? (with the mods, of course). Newer is better for me :)
--
-
Regards, Karl Shoemaker
To contact me, please visit SRG's web site at?
for the current email address.


Chris Baldwin

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At one time, they were made of plastic.

I've seen several of the plastic ones that came installed in manufactured buildings.

Jim W7RY

I saw the?note from Dan about port entry techniques in another thread.? Do I recall correctly these used to be made from copper?? R56 doesn't seem to suggest aluminum for this purpose, but it's been a while since my last read.

So if Tessco makes these entry port devices?of aluminum, what can you all suggest for grounding?this panel to the site grounding system... or does this simply?float leaving the task of cable grounding?to other devices?

John

On Thu, Nov 24, 2022 at 12:31 PM Dan Woodie <kc8zum@...> wrote:

Below is a 2-port 4" entry port I used at my repeater site.? Use a masonry hole saw to cut the holes then mount and seal this plate.? Get cushions appropriate for the cable size and number of cables used.? Below are some examples.

Where we haven't had room to install a cable port entry we have used a waterproof Cable Gland. See the below link for photo of what they look like.

They can be mounted on a small square piece of aluminum plate stock. You end up with sort of a mini cable port entry that is waterproof (and rodent/insect proof too).

They come in metal and plastic. We have used the metal ones.

<>

Joe

Hello Matt, thanks for that very informative post. I help maintain a multi site UHF repeater network which is mostly linked via RF but some sites are AllStar. The hardware and Olivia service you describe may be just the thing for a couple of locations that need a connection but I haven't found a "cheap ham" way of making it happen. Till now :)

Thanks!

On my old radio key ring I have a C2160.

I don't recall what it fits.



Hello Group,
I have a "2131" key. Could not find it on the list. As I recall, it was with some hamfest treasures forty years ago. Motorola??
73 de Tim
AE7TH

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The 2131 is a Chicago Lock key code.
Motorola is not the only user of Chicago Locks.
So this could be for another user of Chicago Lock.

73
Glenn
WB4UIV

I've never heard of a 2131 but I do have a 2253 if I recall correctly. It was a rare bird and only opened up certain Motorola cabinets.. The 2553 was the more common one for the older upright jobs. I wouldn't be surprised if there was some other offbeat versions out there

On Thu, Nov 24, 2022, 10:24 AM TIM HARDY <w7trh@...> wrote:

Hello Group,
I have a "2131" key. Could not find it on the list. As I recall, it was with some hamfest treasures forty years ago. Motorola??
73 de Tim
AE7TH


> On 11/24/2022 8:06 AM K8TB <k8tb@...> wrote:
>
>?
> Folks,
>
> You know when a website has dotted all the dots, when they have an
> article, (needed), that explains just keys.
>
>? ??? ??? This is simply put, awesome!
>
> To all of you, even though I've been in this hobby for 55 years, and put
> my first repeater on the air at the age of 18 (over five decades ago), I
> have learned so much from the folks on this site, and from the repeater
> builder web site. Yes, we should be thankful for our families, jobs and
> homes, but having a group like this gives me just that much more
> knowledge to help out my local amateur radio community.
>
> This is a wonderful group of people, and I thank you you all.
>
> Tom Bosscher K8TB
>
>
>
>
> On 11/23/2022 10:56 PM, Kevin Custer wrote:
> >
> > Corrected the last entry - and here's everything you'd want to know
> > about radio locks and keys:
> >
> >
> >
> > Kevin W3KKC
> >
> >
> >
> >
> >
> >
>
>
>
>

-- 
-----------------------------------------------------------------------
Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
Amateur Callsign:  WB4UIV            wb4uiv@...    AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)  USSVI, FRA, NRA-LM    ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

I have 2 unpopulated PC boards from Sierra Radio used to interface with a MTR2000.? The connectors are not soldered to the board yet.
I don't have a schematic or parts list available for the PC board.? Sierra Radio should be able to supply this?

$29.00 including Priority Mail shipping.

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These are 100% totally overboard for a home.



Use a 2" pvc conduit sleeve (or large enough to pass your current and future needs) through the wall of you home.

73, Jim W7RY

Don't ever use that garbage.? Buy proper entry port, cushions, and boots.? They are readily available from Tessco.? Below is a 2-port 4" entry port I used at my repeater site.? Use a masonry hole saw to cut the holes then mount and seal this plate.? Get cushions appropriate for the cable size and number of cables used.? Below are some examples.? Remember you should have a ground kit on each cable outside of this port bonded to your EGB and a PolyPhaser on the inside bonded to your MBB/MGB - so installing this should be as easy as pushing 1 ft of cable through the port, installing the cushion and boot, tightening it up, and connecting the coax to the PolyPhaser.? Make sure you leave the provided rubber port covers on any unused entry ports.? Whatever you do, DO NOT do the hack thing and try to turn a port cover into a boot/cushion.? I have seen this too many times when idiots take a utility knife and just cut a hole - then they may try to seal it with Butyl which dries out and falls off over time.? None of this stuff is that expensive - just buy the right parts.









Dan Woodie, CETsr
KC8ZUM

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In my opinion...
NO!

That's what calking is for.
These things have horrible return loss figures.

73, Jim W7RY

Is it better to use a bulkhead like this to run cable through concrete block or run a tube with heliax? ?We are in an area where we have small critter problems like lizards and mice.

Thanks and Happy turkey day!!!!

KD6YTS?