The specs are for a maximum pressure at a specified temperature, usually
72 degrees F. PVC softens with temperature so the ratings degrade with
temperature. It is usually not used for hot water service. The specs
say "Not rated for 140 degrees F".
One experience is that sch 40 fittings were
It looks ugly, but schedule 80 wrapped in many layers of duct tape
will launch your projectile of choice with "relative" safety.
Don W4DNR
Quoting David G4FTC :
Thanks for the data on the sch 80 pipe - I assume that the 300+ psi
figures are working pressures which should give a good mar
Grant is exactly right about the cold &
knocking it around. Last winter I was out
in freezing weather and bumped the end
into a rock. The PVC broke in the valve
where the PVC is threaded in. I had to
dremel two opposing slots in the broken
piece and wedge a solid piece of metal in
so I could
The other day a ham friend suggested using a coil ("hairpin") to match
the low impedance of a well-radialed inverted L to 50-ohm coax. This
struck me as a potentially-attractive alternative to a series vacuum
capacitor, but I don't know enough to evaluate it. Thoughts?
--
73, Pete N4ZR
Check
The reason to use a series capacitor is to electrically lengthen the
antenna wire, driving the high current point up the vertical section,
for more efficiency. The capacitor electrically shortened the antenna
to the 160 meter band.. With the right amount added wire and capacitor
the feed point woul
Wasn’t that called a gamma match in the past?
-73- FrankKG9H
kg9hfr...@gmail.com
> On Sep 1, 2019, at 1:46 PM, N4ZR wrote:
>
> The other day a ham friend suggested using a coil ("hairpin") to match the
> low impedance of a well-radialed inverted L to 50-ohm coax. This struck me
> as a
Simple, resonate the vertical at about 1.9mhz. Then add the inductance across
the feed point which may well be in the 2-3 micro Henry region. But use a
variable L and slightly alter the L or top loading to get the match where it's
wanted. I have used a hairpin match and a T Vertical for a numbe
Interesting discussion on shooting antenna wires in trees.
I have used a bow and arrow for 25 years. Cheap practice bow (good for
trees up to 100ft) and practice arrows with an open tip. I fill the tip
with a few nuts (ie nuts and bolts nuts) and tape the end shut which gives
just a bit of
You mean physically lengthen the wire. Unfortunately, the added horizontal
radiation may defeat the intended purpose. Ir pays to model.
Wes N7WS
On 9/1/2019 12:07 PM, FZ Bruce wrote:
The reason to use a series capacitor is to electrically lengthen the
antenna wire, driving the high current
No.
Wes N7WS
On 9/1/2019 11:51 AM, Frank Krozel wrote:
Wasn’t that called a gamma match in the past?
-73- FrankKG9H
kg9hfr...@gmail.com
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Pete, broadly in matching theory, a series-capacitor match can often be
replaced with a series L and shunt C to ground.
Often the topology will be chosen on component value reasonableness and
convenience of what's grounded where. Other times you might have a strong
preference for a matching networ
Ed,
The reason I now only use the spud is I
have no single easy tree to get over, it's
a forest I have to shoot into, and the
arrow is too light to bring itself down
through the branches with a fishing line
attached.
I first used slingshots & the lead weight
was hard to find in the woods.
Guys
Will a invereted L a quarter wave length resonate at a given frequency without
a matching network?
Doug wd8z
Sent from Mail for Windows 10
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That's exactly what I do; shorten the radiator to create a capacitive feedpoint
Z and shunt that with inductance to make a resonant impedance step-up at the
desired frequency.
That said, my original loading wire was some stranded super flexible bare copper
12 AWG that I pickup up at a swap mee
Anything will resonate at some frequency. The question should be will it be a
good match at the desired frequency.
Wes N7WS
On 9/1/2019 4:02 PM, doug dietz wrote:
Guys
Will a invereted L a quarter wave length resonate at a given frequency without
a matching network?
Doug wd8z
Sent from Mail
Matching network does not resonate the antenna
Guys
Will a invereted L a quarter wave length resonate at a given frequency without
a matching network?
Doug wd8z
Sent from Mail for Windows 10
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__
Hi Doug
Ignore those splitting hairs. :)
Yes, and inverted L will represent a load that should work for your radio
without any additional tuners (should).
I run an inverted L right up the side of an 80 ft pine tree and then I have
4 elevated radials. 2 of those radials parallel a fence that su
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