An L network with a coil in series and a 500pf variable to ground might do
the trick. You impedance of the antenna is to low and you need to bring it
up. You can also try extending the top hat wires by 20' each and see what
difference that makes.
Herb, KV4FZ
On Tue, Sep 18, 2018 at 5:44 PM Ash
>
> Herb (KV4FZ) mentioned an L network, and that is what I always use. Very
> simple, and you just plug you're measured complex impedance values (at the
> frequency you want to be resonant) into one of the many online L network
> calculators to determine the amount of inductance and capacitance r
What I don't understand is why would you use more components than needed.
Why a capacitor (possibly vacuum). What is wrong in using a hairpin which
also DC shorts the vertical to ground. A combination of hairpin size and
top loading will give you 1:1 at your favourite 1.825 or anywhere else.
Perha
Your suggestion of a hairpin is a high-pass. Herb's suggestion for a
series-L shunt-C L-network is a low-pass. Sometimes you might prefer one
over the other.
Or choice might be entirely driven by parts on hand.
I happen to have some big old variable capacitors so all my tuners use them.
But a yo
On 9/18/2018 4:19 PM, Joe Subich, W4TV wrote:
2) use a 4:1 auto-transformer at the feed point - your antenna
analyzer says the real impedance is about 15 Ohms. A 4:1
auto-transformer will get the SWR down to about 1.2:1.
Generally speaking, you will get a wider bandwidth with
a auto
f6aoj.ao-journal.com and then « tuning short vertical » , menu left side.
It could help you to match your antenna.
73 to all.
F6FYA / Jean-Paul
Envoyé de mon iPad
> Le 19 sept. 2018 à 20:41, Tim Shoppa a écrit :
>
> Your suggestion of a hairpin is a high-pass. Herb's suggestion for a
> se
My HF antennas are all wire verticals; 20M
vertical, 30M vertical, 40M vertical, 80
INV-V & 160 sloper. Using the Ameritron
remote coax switch it allows me to select
one of these antennas and this allows a
match to everything from 160-6 except for
60 meters which I don't use anyway. All
are
Gary as long as the verticals are isolated above ground when not switched
in. You should be ok. 73 Clive GM3POI
-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary
Smith
Sent: 19 September 2018 20:35
To: topband@contesting.com
Subject: Topband: Multip
Gary,
I am not sure about all bands, but I have done it with 3 bands. I run my
160 inverted L, a vertical for 80 and a vertical for 40 all off of the same
feedline and ground radial system. At least for these three bands, they
don't have a lot of interaction. My 4NEC2 model showed this, and my
e
Several suggestions, some already mentioned -
Although your swr plot shows you are in the ballpark for resonance, the
feedpoint resistance is very low, as mentioned likely 12 to 20 ohms. A
transmission line transformer stepdown will help a lot. 4:1 likely the
best choice. If parts are hard
I suspect your data. For a 0.1 lambda vertical, the radiation resistance will
be quite low particularly with sloping loading wires and with your radial system
the ground loss will be high. Additionally, I think the top loading is
insufficient to achieve resonance. Yet you seem to have it. Yo
Me too. But I wasn't ready to present them yet. I'm away from home at the
moment.
Wes
Sent from my iPhone
> On Sep 19, 2018, at 6:04 PM, Roger D Johnson wrote:
>
> I did a quick model in EZNEC and came up with very different values.
>
> 73, Roger
>
>
>> On 9/19/2018 6:53 PM, Wes Stewart w
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