On 1/13/2024 2:02 PM, email wrote:
With the K4 power (drive) low enough, the amp can make 200W. Maybe not
efficiently.
I regularly reduce drive from K3 or K4 to big amp to run 100W in NAQP,
and on 60M, and 200W on 30M. I do that because I run the K3 and K4 for
two-radio contesting from a
The military isn't chasing DX or contesting ... They need enough
radiation for adequate operation in their networks. In the example, a
resistor in the folded dipole gives them that, they don't care about the
3dB, and a much easier radio system to set up. Little different for us
"Amateurs."
Unless its something like a log periodic, I think anything with those
frequency/SWR specs can only do it with high resistive losses. It
reminds me of the HF dipole B makes for the military: it is designed
to appear to have a low SWR by having 3 db of resistive losses. The
military
Good Evening,
Winter got cold this week. Currently it is 15 degrees F with fresh
snow falling. It is supposed to get marginally warmer by tomorrow.
Sleet was falling earlier, which seems odd considering the temperature.
It must be near freezing wherever it was formed.
The sun is
From your description, something in the antenna system, coax,
connector, balun, antenna is heating and changing value. I doubt it is
the radio, or the amplifier, or the tuner.
That antenna is rated at 250 watts PEP. Sure bet you are exceeding the
power rating with the KPA500 running.
73
Check all of your connections such as PL-259 and SO-239. I once had the same
problem with a dipole antenna and a loose shield wire would disconnect and put
my SWR >9. You could also have a bad kink in your coax cable.
Good Luck
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On Friday, January 12th,
Page 5 of the PX3 user guide has a diagram showing how to do this.
73s
Rob - VA7RPE
On Jan 13, 2024 at 1:59 PM -0800, Steve McKee , wrote:
> Ok, I hooked up the KX3 to KXPA100 today,
> Had to pull the “acc1”connection for the PX3 on the KX3 to connect KXPA100.
>
> How do I put the PX3 back in
With the K4 power (drive) low enough, the amp can make 200W. Maybe not
efficiently. (yes, 200W is only 3db more than 100W) If FT8 RX level
at -24, then 3db may be important ??
steve WB3LGC
On 1/12/24 7:52 PM, Ken WA8JXM wrote:
Why do you have the amplifier running? 30m is as restricted
Ok, I hooked up the KX3 to KXPA100 today,
Had to pull the “acc1”connection for the PX3 on the KX3 to connect KXPA100.
How do I put the PX3 back in the loop??
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That antenna is rated for 250 watts, which is most likely the cause of the
problem. This is common, we upgrade from low power to high and don’t realize
that we need to upgrade out antenna system as well.
For use with the KPA500, you should replace it with an antenna with a higher
rating. These
Please describe the aux cables you have in use between the equipment. It is
highly unusual for the BCD lines to change state during transmission, on any
other time without actually changing the band on the K3.
If you are using very long Aux cables, or have other equipment connected to the
cable
Usually the limiting factor for low temperature in modern equipment is the LCD.
They have a problem crystalizing much below freezing and thus are not usable in
very cold temperatures.
I hope thing don’t get too cold in your area - we are forecast to see 19F here
in SW LA on Tuesday morning.
The C HA-50HD is rated for 250 W SSB or 75 W for digital modes. It gets a flat
SWR with resistive losses in the transformer. That is why the transformer has
heat sink fins. A KPA500 is almost certainly overheating the transformer and
causing failures. I would back off the power to match the
Doug, You didn’t specify which “K” radio you were inquiring about. My K4D
manual page 45 says: 0 C to 50 C or 32 F to 122 F. The K3s manual specifics
0-50 C for frequency stability. The K2 manual does not mention operating
temperatures. The KX3 manual does not specify. I checked the non
Pete, have you tried increasing the transmit delay between your exciter and the
amp? If the exciter continues to transmit briefly after the amp’s relay kicks
out, you could see an swr spike.
73, Lou W0FK
Lou Laderman
Sent from my iPad
> On Jan 13, 2024, at 10:50 AM, Pete Smith N4ZR wrote:
>
I don't have the same equipment as you but I experienced a very similar problem
that I initially thought was caused by a problem with my KPA500.However,
when I looked at the output of my TS-590S with a scope and spectrum analyzer,
I found that it was emitting out of band spurii at the end
I've been operating 160M FT8 recently, and am noticing some odd symptoms
from my amp that seem only to occur in FT8 mode. Even running only
about 1170 watts into a good dummy load, with the KPA-1500's ATU
bypassed and a displayed SWR of 1.0:1 during transmit, as soon as the
transmission ends
What minimum temperature should a K station be kept at during a hard freeze
and is there a cold temperature point at which it should not be powered up?
Please reply to the list and as always do not reply to a digest. Thanks in
advance
for any information.
73, Doug W5JV
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