[SJDXA] K3 Update

Wed Aug 25 14:20:52 EDT 2021

I concur shipping back to Elecraft is the right approach.
I had spent some time looking at how they switch antennas between the Main antenna and the Aux antenna as well as between the main receiver and sub-receiver.  I was trying to figure out how to easily switch my receive antennas between the main receiver and sub-receiver (so I could use diversity). I did find a fairly simple way.  But I also did find that the built-in protection from high RF is only good for a watt or two.  So, it does make sense that either somehow someone transmitted into the main receiver or that lightning/snow static is the culprit. (My vote is for lightning.)  I remember an Acom box that should have prevented transmitting into the K3.  To use diversity, I believe the Beverages are routed to the Main receiver (via the KXV3 module) and the HiZ is connected to the sub-receiver. (At least, that's what I recommended the last time I was down there in 2019.) All of those had outboard protection boxes, too.
I've survived Henri pretty well.  The rope holding the upper horizontal leg of my 160M Double-L wore through so I'm off 160.  Soon a it cools down some, I shoot up another rope.
73,
Gerry, W1GD

-----Original Message-----
From: Bob Schenck N2OO <n2oo at comcast.net>
To: 'SJDXA-LIST' <sjdxa at mailman.qth.net>
Sent: Wed, Aug 25, 2021 11:48 am
Subject: [SJDXA] K3 Update

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, N2OOPresident SJDXAGO SJDXA!!! www.sjdxa.org  ______________________________________________________________
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