Should contest rules allow and act upon 599K QRM reports?

Saturday, 31 October 2009

Elecraft K3 filter offset measurement (8 pole, 400Hz)

Just had a look at my 8 pole 400Hz filter with it set to kick in at DSP BW 900Hz to keep any DSP effects down and the AGC set to off. Did the measurement (using my FT1000MP MkV providing the sig into dummy load with wire to K3 antenna port wrapped round it giving S9 on the K3 meter. The MP has the high freq stab option fitted).
Using the dBV meter on the Elecraft display and resetting it to 0dBV on each measurement by reselecting it on the menu.

Initial results for -6dB points: -265Hz / +198Hz (meaning offset too high by approx 30Hz within 463Hz)

Adjusted 400Hz filter offset value to -0.03

Final results for -6dB points: -235Hz / +228Hz (meaning offset too high by approx 3Hz within 463Hz)

Note that the filter bandwidth was measured dead on 463Hz on both measurements giving me some indication of measurement accuracy.

Monday, 26 October 2009

MM3T CQWW Phone 09

It's the day after CQWW phone 09 and I was so impressed by the K3's performance during the contest, I just needed to share.

I'm not a keen SSB operator, but I like to give some points away. The main thing I learnt this contest was that LO-CUT-HI rocks in SSB! I'd been putting up with horrendous QRM trying to work DX buried between big EU stations. I was using the WIDTH control with not much improvement apparent, when in desperation I decided to try and see if I could winkle the DX out with SHIFT / LO-CUT-HI. The result raised my eyebrows is was so good. I didn't realise that intelligibility could be so good at such narrow (shifted) bandwidths. It made me regret choosing the 2.1KHz instead of the 1.8KHz roofing filter.

On another subject,

This contest the following stations decided to start up on top of me when it was impossible to miss me:
They all suffered from "selective deafness" on a busy 40m.

Out the three, DC4A was the worst, he started up with no QRL at 59+40dB exactly on my frequency. I recon his chosen technique is to pick the least QRM freq, then leave the voice keyer on continuous loop whilst leaving to make himself a cup of tea. When he comes back the QRM he has caused has driven away any occupant (as it's pointless trying to reason with a recording). During the time he QRM'd me, he made no contacts. I had to comply and QSY or lose points being stubborn.

Anyway for the first time it annoyed me so much I nearly gave in with frustration. I went downstairs and had a break and before long was back on 40m doing hunt and pounce.

Another couple of times stations started up impossibly close to me and even though I caught them immediately with "please QSY the frequency is in use" they carried on regardless "selected deafness" style. In one case the station complied to my plea only to move 300Hz further away :-). I think tiredness really comes through in these eventualities and it's best not to be provolked by their stupidity and just to take a break (even though they have just ruined a run into the states after a spot).

Saturday, 3 October 2009

Elecraft K3 Subreceiver (KRX3)

I collected the KRX3 from our local Parcel Farce depot and after 3 nights (2 hour sessions), had it in the K3 and working. The build went very smoothly with all parts present and some extra screws and washers for good measure. Instructions were well written and left nothing to experimentation.

However, I did make one silly mistake where I put the filters in the wrong positions (L-R not R-L) and ended up having to take the KRX3 back out and reposition them. It took me an hour of head scratching and foul language till I realised my mistake :-) (the KRX3 filters are unusually numbered from 5-1 (L to R) so your widest filter goes in far right).

I've configured AUX RX to come from the supplied BNC connector as I don't have a KAT3 installed and I want to be able listen to separate bands. True diversity rx is a show stopper. I have an 80m doublet and a 40m quarter wave vertical antenna and was listening to someone in the EU calling for and working JAs. The JAs were masked on the doublet by EU muppets calling back, but the vertical still allowed me to hear the JAs in my right ear through all the EU QRM in my left ear!

Experience with the K3 main rx has taught me that I only need 2.7KHz tx/rx (5 pole) and 2.1KHz rx (8 pole) roofing filters to cover all modes in the sub rx. This is partly due to a design flaw in the K3 which automatically selects the narrowest roofing filter for the selected DSP bandwidth. If there was a manual option, I would buy and fit more roofing filters on the basis that 'I' could choose when to use them. i.e. The K3 selects a high loss narrow roofing filter (500/400/250/200, if installed) and then tries to amplify the output back to the original input level, just because I selected a lossless DSP filter bandwidth of anything at or under 500Hz. If you don't fit these filters it has to stop with the narrowest roofing filter fitted (2.1KHz in my case). This means less internally generated noise and no QRM difference in certain band conditions, a win-win in my book. Of course there are band conditions which suit having a tight roofing filter, but I'd like to be the judge of that!

Anyway, the usefulness of the K3 has skyrocketed with the addition of the 2nd rx and makes my MkV even more redundant than it was. I guess I'll have to think about selling it on before it dies of lack of use.

Parcel Force and rip-off Britain

My parcel was intercepted by the Glasgow depot of Parcel Force (11 miles from my home).

So in summary:

1) You pay US Postal Services for international delivery to your door.
2) When the parcel arrives in the UK, Parcel Force intercept it and won't deliver to your door.
3) Parcel Force charge £9 "handling charge" for you to come to their depot and collect the intercepted parcel. Parcel Force then collect UK tax (20%) on the item and the original postage charge.


Parcel Force - Charge US Postal Services for delivery within the UK, then don't bother?

US Postal Service - Charge you for delivery to the door, knowing full well they can't or don't have to?

UK government - Charge you VAT on a US postal service that they have a hand in making sure can never be complete.


You - US Postal charge + UK Handling charge + UK VAT on US Postal charge + Petrol + inconvienience + anger at being charged for services you never get.

Welcome to Rip-off Britain!