Fabio,
You've seen my antenna farm -- Beverages run within 20-30 ft of my 160M
TX antenna facing NE. Beverages feed a DX Eng preamp before going the
sub-RX. I don't do anything special to protect the radio, but it does
occasionally protect itself. I also use the Beverages on 80, 40, and
30M, but TX antennas are much farther away (more than 100 ft). This is
at 1.5 kW with a Ten Tec tube amp.
BTW -- I just added a pair of VE3DO loops tuned for 160M and aimed to
EU. Each loop is a rectangle 40 ft long and 10 ft vertical, with the
bottom wire 2 ft off the ground and fed at the center. Details on
OK1RR's website. The two loops are spaced 5/8 wavelength (350 ft). You
probably don't have room for two loops, but you might fit one of them.
73, Jim K9YC
On Sat,3/4/2017 2:11 PM, Fabio IZ4AFW / NZ1W wrote:
Hi Dave,
thanks for the suggestion.
I tried doing a quick measure using a cross-needle SWR meter today,
using the lowest setting.
On 40m the power appears to just deflect the needle, well below the 0.5W
mark. Probably I could say less than 250mW, maybe 100mW.
I usually have an external relay in a box to disconnect the RX antennas
while transmitting, but not today.
I was thinking why the RX antennas remain connected when transmitting if
there's not another use in a typical single-op station.
Thanks,
Ciao
Fabio
IZ4AFW / IO4W / NZ1W
Il 04.03.2017 13:12, David Olean ha scritto:
Hello Fabio
I have two beverages that are somewhat close to my TX antenna. One
had about 75 mw on it during TX while beverage #2 had about 1 watt! This
is enough power to cause damage to preamps, so I made two power limiters
and now the inputs are clipped at about 0 dBm. All it took was two
transformers and two diodes in a box. Do you know what the power level
is on your beverage during transmit periods? Really high power levels
could burn up the transformers. Disconnecting the antenna is a good
idea too.
Dave K1WHS
On 3/4/2017 9:53 AM, Fabio IZ4AFW / NZ1W wrote:
Hi guys,
I was thinking of a possible firmware improvement related to the
carrier operated relay.
I use my radio on a small lot and recently I added a short beverage
antenna for low-bands receiving. My main activity is single-op
contesting.
Because of the interaction between the tx antennas and the beverage, on
some bands I have the COR (carrier operated relay) activating when I use
high power.
I know the good solutions, but my point is different.
As I have the COR activating only when the RX Ant input is selected, why
doesn't the K3 firmware disable it when pushing the ptt?
In fact, when I push the ptt I don't need the RX-ant part to be active,
as I'm transmitting, and -at least in my setup- I have no other
rigs/devices that need that input (I mean, no in-band receivers and so
on).
Instead of using external relays (ptt-activated) that cut out the rx
input when I am transmitting, why the K3 firmware just doesn't disable
the RX ant input on its own (and re-enables it if needed when releasing
the ptt)?
Maybe I'm missing something here, or that could be a nice improvement
for a next firmware release.
Thanks for any comment,
Ciao 73
Fabio
IZ4AFW / IO4W / NZ1W
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