The feedline (if coax) outer braid responsible for imbalance RF
radiation, is fed from the antenna end.
Choking it there eliminates a RF active length.
vk4tux
On 1/12/21 03:48, Dennis W0JX via Topband wrote:
K9YC made an interesting comment in his post, saying that the feedline chokes
sh cubic feet of volume.
Looks like Helium is running about $2 a cubic foot = $66 per use?
Gad. Too pricey for N5OT.
73 - Mark
On 11/8/2021 4:21 PM, Adrian wrote:
Also the disposable party balloon bottles are a waste of $ and would
only inflate 2 to 3 of the balloons here.
Industrial gas suppl
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2nd June 2021
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Even here the industrial stuff is not 'pure' helium.
They don't admit this until questioned. Helium molecules being smaller
leak through the latex skin leaving the bigger air molecules trapped
behind.
After the session, I usually bring the balloons back into the house and
untie them after a
I have been doing it here for well over a year. I originally set it all
up with a 1/4w vertical for 630m,
'which performs very well., Then also 160m and 80m using 3/4w lengths
For 160m I use 90cm latex balloons fully inflated. I use the online wind
forecast showing area
wind velocity and
It doesn't need much swr increase to trip, A rise to 1.7:1 will do it
despite that swr fine for use.
You did not comment on the SPE indicated swr. Can you see it rise just
before it trips with gradual drive increase ?
vk4tux
On 30/10/21 10:59, WW3S wrote:
yep,, did thatdoesnt trip until
Sounds like you are still unsure, and that is a guess. You said the swr
is 1.4:1 , I guess this what the SPE shows with SPE in standby, and txcr
keyed ?
If so when switched to operate, you should be able to gradually increase
drive power form a very low level and raise until you see the
The amp is doing its job, and the swr trip threshold is 1.6:1. It is
best to set the SPE atu toi bypass if used, and use an external
eg; Palstar manual tuner to tune the SPE display 1.10:1 or better on
standby TX and in operate, adj the Tuner input/output capacitors for
best under power,
://wind.willyweather.com.au/qld/darling-downs/laidley-heights.html
for wind conditions , which is useful, but like most weather forecasts,
not always accurate, but a good guide.
This Sunday coming looks like a good time to setup again.
73
Adrian Fewster
On 25/3/21 8:57 am, List Mail wrote:
Hi Adrian
Oops I see now K9FD is in Hawaii, Callsign tricked me.
So he was in the 'dark'.
Vk4tux
-Original Message-
From: Adrian [mailto:vk4...@gmail.com]
Sent: Thursday, 25 March 2021 1:54 AM
To: 'topband@contesting.com'
Subject: Helium Ballon & SPE on 160m FT8
Installed a new LDMOS in my
Installed a new LDMOS in my SPE this week and have it on the Helium balloon up
now ;
154730 0 0.1 974 ~ VK4TUX K9FD +07
Just worked above, must be daylight there now
Adrian Fewster
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Interesting page on the subject here ;
https://ham.stackexchange.com/questions/3675/what-is-the-effect-of-using-different-number-of-radials-with-ground-plane-antenn
On 23/3/21 1:55 pm, Guy Olinger K2AV wrote:
A counterpoise is what we do when the full size of a double-ended
antenna, dipole,
Recycling signals at the feedpoint sounds more like a mismatch swr
situation.
The ground radials form half of the antenna, and that radiation from
ground, in phase with the vertical radiation determines the field
strength and take off angle.
vk4tux
On 23/3/21 11:31 am, Charles Moizeau
Intend to do this again tonight here in VK4, as conditions look ok.
Please look out for me on 160m FT8, will be good to check sig reports.
I may look at FST4 also. 200w only. 1/4w vertical
73
Adrian Fewster
vk4tux
On 9/3/21 9:29 pm, Adrian wrote:
On FT8 160m now using Helium Balloon
On FT8 160m now using Helium Balloon antenna, 40m high & 200w only (amp
getting repaired).
vk4tux
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
, whom I
see but cannot decode yet on 300, but I have worked on 60.
Thankyou
Adrian Fewster
vk4tux
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Hi Mark
Glad you were able to work VK3IO and VK3HJ.
I pulled out of that opening in deference to others here due to spurious
products on my transmission.
Best 73
Adrian VK2WF
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mark K3MSB
Sent: Sunday, 1
Hi Steve
This evening (29 March) was much better, a number of RBN responses from AA4VV,
VE7CC-7 and W4KKN.
It opened up around 10:45z. Thanks for the QSOs with VE3MGY, N0FW and N7UA.
73
Adrian VK2WF
From: VK3HJ [mailto:vk3hj_l...@barefoothorse.com.au]
Sent: Thursday, 29 March 2018 6:58
Yesterday evening they were S9 on my poor 6m high INV-L. The 1810-1820
interval is unusable here.
73 Ady YO2NAA
On Tue, Feb 20, 2018 at 11:09 PM, Jean-Paul Albert via Topband <
topband@contesting.com> wrote:
> Yes Mark , around 6 pm GMT time louder than the days before.
> Shorter propagation by
Sorry it seems the link I posted got broken.
https://www.facebook.com/photo.php?fbid=440029073004475=pcb.745473342286
826=3=1
73
Adrian
VK2WF
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Adrian
Van Der Byl
Sent: Thursday, 4 January 2018 9:44 AM
Adrian
VK2WF
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Mike
DeChristopher
Sent: Thursday, 4 January 2018 6:28 AM
To: topband@contesting.com
Subject: Re: Topband: Capacity Hat Wire Size
Bruce,
I used to resonate my tower on 80m with 22 ga wire
: Wednesday, February 11, 2015 2:30 AM
To: Adrian Fabry
Cc: topband@contesting.com
Subject: Re: Topband: Inverted-L with coil on the top of the vertical
section
Ady - you might consider using a Folded CounterPoise, designed by K2AV, for
your radial system. I have one on each of my Inverted L
Hello all,
I'd like to build an Inverted-L antenna. Unfortunately the vertical section
will be only 8m (26 ft) high and the radial system not great (maybe 5 to 10
wires laying on the ground)
The simulation (with MMANA software) indicate 3.5 +j0 Ohm impedance. This is
very low so I think most
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