CQ160 contest 2020

Having had so much fun in the ARRL 160 contest I returned do the CQ 160 in January from DEMI. To avoid the previous issues with connecting in Charlotte I flew on an American Airlines codeshare flight which was on a BA plane direct from Gatwick to Orlando, arriving early at 1430, Steve and Sandy met me at Orlando and after a fish supper we drove the 3 hours to Live Oak.

The rules for this contest are not quite the same as the classic CQWW rules. Multipliers are US states+VE provinces+countries. Although DX stations (and only DX stations)  send their zone, they dont add to the  multipliers!

The contest started at 1700 local on Friday under the call K0DI. Unfortunately the starting operator was stuck on a plane at the gate in Washington, so I was volunteered to start. Calling CQ for 10 minutes, nothing much happened, then the pileup started, which was a new "run" experience, which I continued for 2.5 hours before switching to mult duties retiring at 2300 I returned at 0600 and operated till the band closed at 0830 working some JA but no VK/ZL

Having not experienced the overnight shift I returned at 2300 to teamup with Steve. I ran , he searched. I ended up running for 8 hours. The band closed around 0800 sunday morning again . We resumed at 1600 that afternoon  after a visit to the club shack and surprisingly had 17 qsos in the last hour

For light entertainment on the monday after the contest we replaced the power supply in a quadra VL1000 amplifier which had been hit by lightening.

ARRL 160m contest

While attending Microwave update I managed to get an invite to operate the ARRL 160m contest from the Downeastmicrowave site in Florida

I flew from Heathrow on Dec 3 to Orlando via Charlotte, NC. It was to be my first flight on an AA Airbus made plane. Unfortunately it broke so we spent two hours getting it fixed at Heathrow. This resulted in missing the Charlotte connection and being put on the standby list for the next flight. Luckily I was 1st on the standby list and was the only one (of 36 standby) to board. Steve and Sandy met me at Orlando and after supper we drove the 3 hours to Live Oak

The station and antennas were all ready to go, so all i needed was a training session which was easy as we were to use a pair of K3, The available multipliers were ARRL sections (83) and countries. The contest started at 1700 local time I shared the shift to 0300 doing most of the "running", then had a sleep.  The band closes at 1000 and we resumed at 1500. Again I operated till 0200 then sleep. During this period we managed to work the final two sections (NL and ND) needed for a clean sweep of all 83 sections. The contest ended at 1000 local time. The final claimed score was as follows:-



                             Band     QSOs     Pts    Sec
                               1.8    1314        3201  136                     Score: 435,336

The final result:-

The Transmit Antenna

After the contest i hooked up the 1000' NE beverage to my RSP2PRO to take a listen on 474kHz WSPR. I was surprised to see so much of G0MRF:-

191210 0006   1 -30 -0.19   0.4757844  G0MRF IO91 37           0  5279km
191210 0138   2 -25 -0.23   0.4757845  G0MRF IO91 37       
191210 0208   2 -26 -0.23   0.4757845  G0MRF IO91 37
191210 0216   2 -23 -0.36   0.4757843  G0MRF IO91 37
191210 0232   2 -25 -0.27   0.4757845  G0MRF IO91 37 
191210 0238   1 -28 -0.27   0.4757845  G0MRF IO91 37
191210 0304   3 -23 -0.27   0.4757845  G0MRF IO91 37   
191210 0548   1 -28 -0.53   0.4757846  G0MRF IO91 37
191210 0602   2 -27 -0.53   0.4757845  G0MRF IO91 37   

Feature upgrades for the 432MHz Solidstate Amplifier

Having upgraded the 2m solidstate amplifier I decided I should do the same upgrade to the 432MHz Amplifier.  The original writeup is here The Two same features were needed:-

1. There is no bypass position, so one cannot test the antenna SWR before letting the amplifier use it. This cost of the lack of this feature was learnt the hard way on my 70MHz amplifier
2. Currently the Elecraft K3 keys the DEMI transverter which keys the amplifier which sequences the antenna relays and preamplifier. There is no output for the Amplifier to properly sequence the DEMI Transverter along with the antenna relays and preamplifier, this needs to be added.

A bypass switch was added to the front panel along with a bypass LED. A phono socket was added to the back panel for the Transverter output. An hour was spent adjusting the PIC code and all feature additions were accommodated.

PA checkout day

Provoked by an email by G4BVY after borrowing his 1kW 30dB Bird Tenulune I decided it was time to test out some amplifiers

First up was my Elecraft KPA500. It still had the old V1.11 software so this was upgraded to 2.23. It was then tested out and worked fine, a good tryout in preparation for this weekends ARRL RTTY contest

Next up was the 70MHz amplifier. Previously I had acquired a DEMI 48V 50MHz 300W PA. As the KPA500 gives me 500w on 6m it was decided to put it on 4m. Steve told me the only thing that would need changing is the low pass filter. Looking in the junkbox and finding some UNELCO caps and some 2mm silver plated wire one was built and installed.

Next a 48V power supply was needed. I had bought an Erskine one from Jim GI1CET on ebay (I first saw them when he had them at the EME2012 conference but was too late to get one) Unfortunately it produced 54V, bit high for the amplifier. Using the instructions provided,  the cover and sisterboard were removed and a 220k resistor put in parallel with the 22k resistor to the right of the voltage set pot. This gave me the 47-50V range which was ideal

Hooking up the PA to the output of the DEMI 70MHz xverter (configured so that whatever i did it could only run 10W maximum, rather than its normal 35W) 8W gave me 370W on 4m . A quick test showed that it still gave 400W  on 6m for 6W of drive, both of which were acceptable

Multiband 13cm Transverter

One of the issues with 13cm EME is that more than one frequency band is in use. Europe (mainly) uses 2320MHz. Australia uses 2301MHz. USA uses 2304MHz. Japan uses 2424MHz, To work Europe from the USA one transmits on 2304MHz and receives on 2320MHz.  Until recently I used a 2304/144MHz with an FT847. 2304Mhz converts to 144MHz and 2320MHz converts to 160MHz on which the FT847 can operate. Having disposed of the FT847 and now I use the Elecraft K3 which only works from 144 to 148MHz it was time to  work on another solution

About 6 months ago I started on a suitable transverter based on some components I had lying around. A packaged mixer, 3.9GHz filter that retunes to 13cm, spare 13cm preamp and a DEMI TCK. Today I actually finished it. It produces 50mW and has a 0.9dB noise figure. It has an internal 10MHz crystal oscillator and provision to use an external GPS derived 10MHz reference. Provision was made to work crossband, the receive and transmit local oscillator frequencies are set with a pair of rotary switches

Transverter Front Panel View

Transverter Top View