[SJDXA] K3 Update

[Bob Schenck N2OO]

SJDXA members,

 

Here is the overview on the SJDXA K3 issue.

This was all reviewed with Elecraft tech support, fyi.

 

As you already know, we discovered that the radio was not receiving any
signals when using either ANT 1 or ANT 2 which are the two main SO239
antenna ports on the radio used when operating normal transceive.

Upon further testing we discovered that the radio was receiving OK when
switching onto the RX ANT jack.

When the radio is switched to the RX ANT jack, it utilizes the main receiver
which is the same receiver as is used by ANT 1 and ANT 2 except that the
routing is different. When using the RX ANT jack, the routing is basically
direct to the main receiver board. However, when using the ANT 1 or ANT 2,
the routing first goes through the ATU and the RF Board before it gets to
the main receiver board. The second receiver board is used by the SUB
Receiver (I did not test it but asked Elecraft to do so)

Knowing this background, Elecraft tech support feels that the issue (based
on their experience) is on the RF Board pointing to two diodes but this is
not 100% certain. They have initially diagnosed the  problem being caused by
RF OVERLOAD. This "could" be from the second radio in our setup accidentally
transmitting into our K3. Or perhaps a static discharge while on the
transmit antenna. Since the RX ANT was being used, the main receiver board
was not connected directly ANT 1 or ANT 2, thus why the receiver board seems
to be OK.

 

This makes sense since the last times that this radio was in use was for the
2019/2020 160 Contest season. The station was shut down from March 2020
onward, and the radio was removed in the early Fall and stored in a tub in
my closet here at my house.  In all of these contests, the radio was used
exclusively using the RX ANT hooked up to the beverage antennas. We would
not have noticed this problem. When we brought it back and  tried to use it
a couple of months ago at the site, it was still setup for TX INH and RX ANT
switched on but when we tried to use it in regular transcieve, we could not
receive any signals.

 

Although Danny W2NO and Bob W2ARP offered to look at the radio, the
executive board decided to go ahead and send the radio to Elecraft for
repair and for an official diagnosis as to what caused the problem. This way
we "MIGHT" have grounds for submitting an insurance claim with our ARRL
equipment insurance. 

 

I have decided to handle the return/repair myself. I have received an RSA
from Elecraft and I am shipping the radio to them today. I will cover the
shipping and repair costs for now. If an insurance claim can be made, we
will handle that as well. When this is all done, if there is any expense
left over, I am opting to "ask" our membership to "pass the hat" and
contribute towards it if this is necessary. I do not want our treasury to
take a hit. So, when further details come along, I will share them with you.

 

 

See ya' in the Pileups!

73!

Bob Schenck, N2OO

President SJDXA

GO SJDXA!!! www.sjdxa.org

 

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