I wish they were all N or HN or DIN Connectors. I have seen some pl259, and
even N connectors do ugly things under load, admittedly more at higher
frequencies. Commercially we are using DIN Connectors more and more. In part
because of the Power of several combined transmitters on one line at380 &
700-800-900 mHz, but more for low PIM. I compromised once on a cheap PL259
connector I had in a drawer and while tuning up an LK550 (HF) got quite a
loud surprise. It blew the RG8 right out of the connector and made quite a
fire ball. One of the tubes had a bad reaction to that. It was costly. I
have noticed on the captivated pin (crimp on) N connectors, they get pretty
hot with just a couple hundred watts of 800 mHz. We use some crimp on
connectors for low power mobile, low power control stations, etc... but
never outside and never never with high power. There is no substitute for a
properly soldered and tightly installed connector that is trimmed properly.
Just like getting over 500 hp in a car, things start breaking fast, getting
QRO, similarly things start breaking and sometimes catching on fire. It is
such a simple cheap thing to buy and install the best connectors for
everything past the amp and to the antenna. I think it is a terrible place
to compromise. I would rather do that at the low power end of things. I
think Henry had the right output connector on the 4k Ultra. Sam N9FUT
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of David C. Hallam
Sent: Tuesday, May 01, 2012 4:33 PM
To: amps@contesting.com
Subject: Re: [Amps] every db lost re Tubes vs. Solid State
I realize that the investment of a proper crimping tool and dies for UHF is
an investment of not insignificant proportions. But compared to the
investment in a modern SS transceiver, it's a small price to pay to get the
expensive RF to the antenna. In every comparison test I have seen, crimped
connectors were equal to or better than soldered connectors.
I gave up on soldering braid on PL-239's sometime ago.
David
KW4DH
On 5/1/2012 4:13 PM, Manfred Mornhinweg wrote:
>> Some years ago, I discovered a 'cure' for the problems brought to my
>> station by cheapie connectors. They ALL went into the S***can!
> Much the same here. And it's a real problem, because every connector I
> can buy locally (Chile) is Chinese-made, and while the best of them
> are satisfactory, most of the rest are junk.
>
> But not always is the problem attributable to a bad connector. Very
> often it's bad installation. I don't know how it's in the USA, but
> around here it's truly surprising how few hams know that the holes in
> the sides of a PL-259 connector are there to solder the braid! People
> will strip the coax, push or thread it into the PL-259, solder the
> center conductor, and leave the braid to contact the shell by
> proximity, telepathy, good luck, or by the never-failing (so they
> think) spring action of the plastic jacket...
>
> Only the internal conductor is hot with RF, right? So it doesn't
> matter if the braid makes no contact, right? That's what they think.
>
> And then there are those who have emancipated from this step. They
> will push the coax cable into the connector, and then try to somehow
> patch those pesky solder holes with some half-melted, pasty solder.
> The braid inside stays untouched.
>
> Or those who want to do it right. They push in the cable, then heat
> the whole connector with a torch, and flow abundant solder into those
holes.
> This time the braid gets properly soldered to the body. And so does
> the center conductor. To the body, I mean.
>
> I have held workshops at three different radio clubs, to try teaching
> people the correct installation of a PL-256 connector, and I have
> found that many hams just plainly lack the ability to understand why
> it should be that way, or the discipline to actually do all necessary
> steps, specially tinning the connector body on the inside before
> pushing the cable in, and tinning the braid...
>
> I have seen PL-259 connectors in which the braid had been unbraided,
> twisted into two bundles like Salvador Dali's mustache, pulled through
> the solder holes, and the two ends knotted together outside the
> connector's body! A great, safe contact, sure! ;-)
>
> Oops, I'm in ironic mode today. Forgive me... Must be because it's 1st
> of may...
>
> Manfred
>
>
> ========================
> Visit my hobby homepage!
> http://ludens.cl
> ========================
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>
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