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QRT for decades now getting the urge to go online again

Hi guys,

Could you tell me what sort of wattage a soldering iron needs to have
to cope with soldering co-ax into PL509s?

TIA
--

Cheers

DrT
______________________________
We may not be able to prevent the stormy times in
our lives; but we can always choose to dance
in the puddles (Jewish proverb).

QRT for decades now getting the urge to go online again

Hi guys,

Could you tell me what sort of wattage a soldering iron needs to have
to cope with soldering co-ax into PL509s?

The PL509 is a vacuum tube... I assume you mean a PL-259 "UHF" connector?

They need a good deal of heat delivered, due to the large metal mass.
A small iron will heat the connector slowly... by the time you manage
to make a solder bond, the cable itself will have been heated up a lot
and there can be problems with the dielectric melting. An iron with
higher wattage (and/or lots of mass, well heated) can make a quicker
job of it and let you make the solder joint more quickly.

I've had the best luck with a full-sized Weller soldering iron (the
140/200 watt variety). I think I recall doing one or two with a
Weller WTCP iron using a large tip, but it wasn't easy. Butane-fired
portable soldering irons are another possibility... some of these can
deliver a lot of heat.

Another possibility is to hold the connector and cable in place with a
clamping arrangement somehow, pre-heat the connector with a hot-air
gun (a hair dryer will do) and then finish the job with a
smaller-wattage soldering iron. By preheating the connector you
reduce its tendency to sink heat away from area that you're trying to
solder.

There are some alternative PL-259 connectors, which use a crimper and
a proper die set rather than soldering. See the discussion at
http://www.eham.net/articles/19257 for a look-see. A properly-done
crimp can be just as permanent as a solder junction... sometimes
better.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

QRT for decades now getting the urge to go online again

On 3/17/2012 10:06 PM, DrTeeth wrote:
Hi guys,

Could you tell me what sort of wattage a soldering iron needs to have
to cope with soldering co-ax into PL509s?

I've never had luck with irons: I use a soldering gun. The Weller 140
watt model works OK.

If you have the choice, I recommend switching to BNC or N connectors:
they're much easier to assemble, and have far less loss.

Bill, W1AC

--
Bill Horne
(Remove QRM from my address to write to me directly)

QRT for decades now getting the urge to go online again

On Mon, 19 Mar 2012 12:10:20 EDT, just as I was about to take a herb,
Bill Horne disturbed my reverie and wrote:

I've never had luck with irons: I use a soldering gun. The Weller 140
watt model works OK.

Thanks Bill, it is on my shopping list ;-).
--

Cheers

DrT
______________________________
We may not be able to prevent the stormy times in
our lives; but we can always choose to dance
in the puddles (Jewish proverb).

QRT for decades now getting the urge to go online again

On Mar 19, 11:10 am, Bill Horne wrote:

If you have the choice, I recommend switching to BNC or N connectors:
they're much easier to assemble, and have far less loss.

Hadn't thought about the loss perspective. I don't care for the
PL-259's tendency to not make good connection on the pin after a few
insert cycles and I hear that N connectors are a bit better. But I've
not considered BNC, at least for HF work. I use them on VHF/UHF but
my power levels are well under 50W and SWR's are all fairly reasonable
(under 3:1).

Am I safe using BNC at 100W on HF with SWR's in the 5:1 range? What is
the breakdown voltage of a BNC connector?

-= Bob =-

QRT for decades now getting the urge to go online again

On Tue, 20 Mar 2012 00:15:44 EDT, just as I was about to take a herb,
KC4UAI disturbed my reverie and wrote:

But I've
not considered BNC, at least for HF work.

Though it may be an impure thought, but don't HF commercial rigs all
have SO 259s? Are adaptors available?
--

Cheers

DrT
______________________________
We may not be able to prevent the stormy times in
our lives; but we can always choose to dance
in the puddles (Jewish proverb).

Quote:

Originally Posted by DrTeeth (Post 788676)

But I've
not considered BNC, at least for HF work.

Though it may be an impure thought, but don't HF commercial rigs all
have SO 259s? Are adapters available?
--

Cheers

Yes - but the adapters are quite lossy.

QRT for decades now getting the urge to go online again

In article Channel Jumper writes:

DrTeeth;788676 Wrote:

But I've
not considered BNC, at least for HF work.

Though it may be an impure thought, but don't HF commercial rigs all
have SO 259s? Are adapters available?
--

Cheers

Yes - but the adapters are quite lossy.

Actually, I have not found significant loss in any of these adapters
I have used. If they had much loss, they would get warm (or hot) when
transmitting, and none I have used do.

Alan

QRT for decades now getting the urge to go online again

In article Paul W. Schleck " writes:

Reading around on the subject, it seems that there are different kinds
of losses in connectors and transmission lines, and not all of them will
cause heating at the junction or interval where the loss occurs. Some
knowledgeable amateurs have noted that we sometimes confuse transmission
losses and insertion losses. Transmission loss, either Ohmic resistance
or dielectric, will be dissipative, and directly heat the transmission
line where the losses occur. Insertion loss, such as from impedance
mismatch, results in power being reflected. Even impedance-matched
connector conversions (50 Ohm to 50 Ohm) may still result in some
impedance mismatch due to practical limits on their physical design,
including their actual non-constant impedance that can vary with
frequency, and the quality of their connections, particularly after
long-term exposure to the elements. This is where the imaginary part of
complex impedance, also known as reactance, comes in.

The question being addressed was the losses of an adapter when connecting
a cable to an HF rig built with a UHF connector.

The adapters are very short sections of transmission line. The Smith
chart works here, too. Even with a substantial impedance mismatch through
the connector, the segment is very short with respect to a wavelength, and
will not provide a significant input impedance mismatch, if the output side
of the connector is connected to a 50 ohm load.

5. Insertion loss for RF connector adaptors

"1/4 to 1/2 db per connector is the loss I've always heard."

http://www.amsat.org/amsat/archive/a.../msg00214.html

I suggest measurement is a better way to determine the truth. These
claims are easy to test --- measurements I made some years ago didn't
support such claims. In fact, if you are getting such substantial losses,
it is probably time to investigate other possible causes.

Alan

QRT for decades now getting the urge to go online again

Maybe my answer was not clear enough - anytime you make or break a connection between the coax and the shield and a connector - some loss occurs.

When you start stacking one adapter on top of another adapter and when you use a more lossy coax - the losses multiplies.

As a example - lets say you spent $6000.00 to put up a 100' tower, a SteppIR DB antenna and a cheap Ham IV rotor and then you skimped on the coax and used some cheap Radio Shack RG 8 - open braid wire

Lets say the beam antenna produced 12 db of gain on 20 meters and the coax threw away 3 Db in 100'. Lets also assume you used a good Amphenol PL connector and one connector on each end, had one half of one Db of loss.

You just threw away 4 Db of signal.
Knowing that 3 Db / actually 2.85 is equal to a loss of 1/2 the signal - its like substituting the SteppIR DB antenna for a cheaper model.

Now - we are not just throwing away receive power, we are also throwing away transmit power / and i'm not even going to get into the costs associated with that.

To take it one step further, lets say we put up a 440 MHz repeater and we use the same Radio Shack RG 8 coax and the same PL connector @100'...

What was only 3 Db of loss at 14 MHz is now 16 Db of loss at 440 MHz.
So we go to a better grade of coax / probably hard line, and we use $150.00 connectors on each end.

We still need to concern ourselves with loss.

If we throw away even 1/2 of 1 Db with every connector and we have one connector at the top of the tower, another connector at the ground plate, another connector at the bottom of the tower, another connector on the wire going to the transmitter building, another connector at the transmitter building - before the coax enters the building, another on the other side of the ground, another at the duplexer, another at the transmitter - it isn't very long before all those connectors adds up.

When you get into Microwave frequencies it gets even worse.

Look at the cost of a 1000 watt amplifier for 14 MHz and compare that cost to a 100 watt amplifier at 2.4 GHz and then tell me which is cheaper...