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Sunday 5 March 2017

Asked... have I built a 30m 4SQ?

Interesting question... have I actually built a 30m 4SQ and will I have it on E5..ho hum... disbelieving toe rags perhaps... Honestly use depending on location but I't is travelling with me.

Anyway as was about to pack up the bits I thought I'd show the guts of the kit. The 4 GP and feeders are already in the bag packed. I am sure people don't need to see those :-) The PCB I was given came from SJ2W contest station. I had bodged a point to point version before following ZL2IFB's designs. It all sits in an IP56 (or was until I drilled holes) box with a clear cover, off for photos. I liberally cover all connectors with liquid rubber once it is in place to reduce the effect of salt corrosion etc.

Anyway couple of photos etc.. as was just confirming with the longer control cable and the actual voltage needed (12V not enough) needs to be about 14V at the control box to switch the relays.

Boxes left to right... Ex ATX PSU (12V) into KX3, short feed into 4 SQ hybrid coupler, short feed into silver box which is dummy load, grey box is 4 SQ controller and dummy load RF sense. White cable is the actual control cable. 2x100ohm resistors in parellel as load on all 4 ports. I kept adding AA batteries until the relays actually switched and held in place... 14V so now I know... so I'll use a 12V powered 15V airplane laptop adapter I have. I also tried the RF sense with 100m of RG174 but no difference, I'll have 100m of decent coax with me just for this but I can double up as feeder for something else.

Scope probes attached and you can see the different signals at different phases. I'll tweak the setup on E5 for directivity I need.



Bengt-Erik Norum said...

I've read your blog for the last year or so. Just noticed the E5 plans. Having just returned, I wish you well on your trip. It will be incredibly difficult not to have a fantastic time.


M1KTA said...

Hi tnx... please can we email as would be incredibly useful to get an idea about propagation right now. Emailing you on qrz contact, You can find my contact details on QRZ.

M1KTA said...

BTW CW and Digital focus as you probably already know.