Mini UHF Connectors

[JD]

Is the Motorola (AMP) mini uhf male the connector of choice, or are there other brands that seem to work. I have had problems with them coming loose.

[tvsjr]

Not from my experience. I much prefer the RF Industries RFU-600-6, which has a separate center pin. That said, the Mini-UHF is generally a piece of junk anyway - no idea why Motorola chose them, especially when most of their Euro radios have BNCs.

What part is coming loose? The connector from the coax, or the connector from its mate? If the connector's coming off the coax, you're either exerting too much stress on it, or you're not getting a proper crimp (wrong sized dies?)

[Al]

The Amphenol RFX series is also 3 piece, and if properly crimped I've had no problems with them. Like the RF Industries ones, they're probably a few cents more per unit, but worth it in the long run.
Crimp BNCs can be probematic too if they're not crimped correctly, but they're a constant impedance connector which may be required in Europe at all frequency bands. Using a non-constant impedance connector like the mini UHF(which is better than the older full-sized UHF) doesn't make any significant diffference until you get up above 800 MHz or so.

[JD]

The outer conductor keeps coming loose, I always solder the center pin.

Thanks.

[tvsjr]

I never solder the center pin - don't see a need to do so, plus it screws with the impedence of the connector even further.

I would suspect too much outer jacket being stripped away (check strip dimensions), or an improper/ill-fitting outer ferrule crimp die.

[escomm]

Almost through my most recent of 400 Mini UHF from /\/\ (they are made by Tyco according to the bulk box) and I have not had any problems with the ones that were properly installed. I had a handful of elbow connectors that had female connectors too small, and they'd latch onto the male pin of the Mini UHF and would rip the center conductor from the male when disconnected, but I've since started using RF Industries elbows and have not had any problems.

The biggest problem with Mini UHFs is that they rattle off the radio much too easily. It's real important to make sure the triangles on the male mate into the triangles female, this will aid in reducing self-disconnection. I've found a quarter turn with a needlenose pliers past "finger tight" will usually solve this, in addition to the making sure the triangles match.

As always, 30 seconds of prevention is worth an hour of bounceback warranty labor.

[JD]

What brand of crimper is used ? I went to soldering due to previous post on here that stated crimping could ruin the female connector on the radio.

[tvsjr]

I have one of these kits:
http://www.tessco.com/products/displayP ... ventPage=1
I use whatever dies are specified for the connector. I tend to stick with RFI connectors because I know this kit will work, and to keep my documentation collection down. My connector kit has engineering drawing for all the connectors I typically use with crimp and strip dimensions.

I've certainly never seen a connector on a radio damaged by a crimp connector... since that's what Moto supplies, I'd doubt it would cause a problem without doing something seriously dumb.

Escomm is definitely right about the 1/4 turn with pliers... this should be policy for UHF as well as Mini-UHF connectors. Take care that you don't deform the outer ring and squish it into an oval - seen it happen before, couldn't figure out why the connector was being so strange threading up.

[jackhackett]

I've certainly never seen a connector on a radio damaged by a crimp
connector... since that's what Moto supplies, I'd doubt it would cause
a problem without doing something seriously dumb.

Escomm is
definitely right about the 1/4 turn with pliers... this should be
policy for UHF as well as Mini-UHF connectors.

I've seen them damaged. The ones with the pin crimped on the end can tear up the connector on the radio. At one point Moto was shipping some radios (MCS2000, maybe others) with one of the 3 piece gold pin type connectors in the box and a note that using other types could void the warranty, so apparently it was a big enough problem for them to notice.

Moto also has a tool for tightening them, it's a little metal thing shaped like a plastic cable clamp, lets you get a good grip on the connector without damaging it like pliers might do. They were shipping them with some of the higher end radios such as XTLs... not sure if they still do that.

[xmo]

"...Moto also has a tool for tightening them, it's a little metal thing shaped like a plastic cable clamp..."
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HLN6695A relpaced by REX4584A CONNECTOR TOOL FOR MINI-UHF, $41.28

[alex]

"...Moto also has a tool for tightening them, it's a little metal thing shaped like a plastic cable clamp..."
----------------------------------------------------------------------------------------------------------------------------

HLN6695A relpaced by REX4584A CONNECTOR TOOL FOR MINI-UHF, $41.28

You don't happen to have a photo of what $41.28 gets you do ya?

-Alex

[tvsjr]

"...Moto also has a tool for tightening them, it's a little metal thing shaped like a plastic cable clamp..."
----------------------------------------------------------------------------------------------------------------------------

HLN6695A relpaced by REX4584A CONNECTOR TOOL FOR MINI-UHF, $41.28

You don't happen to have a photo of what $41.28 gets you do ya?

-Alex

I bet it's a metal cable clamp... a loop with two screw tabs sticking out. A proper-sized one would tighten down a mini-U just fine...

[Bat2way]

What brand of crimper is used ? I went to soldering due to previous post on here that stated crimping could ruin the female connector on the radio.

The damage caused to the female connector was always attributed to an improperly crimped center pin (i.e. crimping tool not at a 90 degree angle to the male pin causing a turn out and damage when inserted) and the crimp not at the connector end, but back a bit causing the same problem. Some connectors also had a "longer" center pin causing the not-fitting-snugly problem. Agree with the little extra tightning on the ring, but a simple pair of pliers and some due diligence works fine.

[jackhackett]

Jeepers creepers batman! $41???? Are you sure that's not for a 10 pack?

I don't have a picture, but I can describe it..

It's a piece of thin black spring steel (about the same stuff those little spring clamps you get at the office supply store for holding papers are made from), about 3/8" wide, formed into a circle with about a 30 degree gap, at the gap the ends are bent out to make two tabs, one about 1/2", the other about 3/4" with a hole (probably to put on a keychain or something).

Slip the gap over your coax, slide the circle over the connector body, squeeze the tabs together and tighten the connector... it grips enough to get the connector good and tight but slips before you can get enough torque to damage anything. Next time you sell an XTL check the box for one and pocket it!