Wednesday, December 29, 2010

The Christmas VHF/UHF cumulatives

Although I don't enter the contests as such, I always enjoy taking a few moments to try and make some contacts in the RSGB Christmas VHF/UHF Cumulatives. I particularly enjoy the multi-band element - where you work someone on one band and then try and work them on the other bands that they have available.

This year, I had 144 and 432MHz available as per normal, but I thought I would try on 70MHz FM as well. In theory, I have 70MHz CW/SSB, but as you will remember, the FT847 has such a poor receiver for weak signals, it's not really worth using in a 'tropo' context. I missed most of the first session, but was intrigued to hear 2E0NEY from near Bath on 70MHz FM, on the Wouxun handheld, as I was coming back from a walk. Naturally, I called him, but alas, I still haven't made a QSO on the handheld!

Some of the notable QSOs from the two sessions; ON4WY was worked on 144MHz in two sessions, GW8IZR from Anglesey, (IO73) was a very welcome one on 144Mhz. It's not that far, but the antenna isn't that good to the north as there are some local obstructions. It was good working Dave, G4ASR on both 144 and 432MHz. I even heard him a couple of times on 70MHz FM but didn't manage to attract his attention! Stewart, G0LGS from Cheltenham was loud on both 144 and 432MHz which I thought was good going, considering the path over the Cotswolds. Similarly, Brian, G6HIE in Worthing, under the South Downs was doing well and it was fun to make it on both 144 and 432MHz with him. I should really have tried on 70MHz FM - could be an interesting path!

Chris, G4CCC was the best DX on 70MHz FM at 42km, only just further than Colin, G3TA at 41km! Lots of fun trying a bit more 70MHz FM and I'm confident the gear is working reasonably well now.

No great DX in the sessions, but an enjoyable mix of contacts on different bands during the sessions

Monday, December 27, 2010

What Santa brought to me - a Pentaflex PSU

Santa was, as usual, very generous in his, er, deposits here. There were no specific amateur radio themed gifts this year, as I am well provisioned in that department! I did, however, have a couple of things for my astronomical telescope.

One of these was a Pentaflex 'Mobile Power Station'. This looks like a giant torch, but is in fact, a great big rechargeable battery. The idea was to use this for my telescope which otherwise uses a gazillion AA batteries to guide the tube onto the correct target and it can go through them pretty quickly! I've got more crafty and thrifty about moving the telescope around, but I realised that the PSU for the scope would be a good idea.

Of course, the unit will not just power a telescope! It will be absolutely ideal for powering an FT817 or similar on holiday. It's relatively portable, though quite heavy - so I don't think it's the answer to carting up a mountain for SOTA or similar activities - but definitely a great answer to having plenty of 12v readily available.

70MHz FM: Or when 3 stations came back to a CQ...

Over the last couple of days, I've had the 70MHz FM set on when I've been in the shack. I've probably said, but the set is an converted Philips FM1000 series set.

A few days ago, I called CQ and Dave, G4AQK from Swindon called me and asked if I knew there was a lot of hum on my transmission. I didn't but, switching on the monitor receivers confirmed the issue. I soon found that if I touched the case, the problem went away. I tried various earthing points without any success. Caught up with Rob, G4XUT a bit later and he suggested that it might have been an RF feedback issue.

Bearing in mind Rob's suggestion (which I was quietly a little sceptical about, as the issue seemed to be independent of power level) I grabbed a ferrite ring and put it on the power lead, close to the rig. That solved the problem - so I forgot about it.

A few days ago, I called CQ on 70.45MHz FM again and thought I'd check the transmission. Despite the ferrite ring, the hum was back! Tried another ferrite on the microphone lead, but that didn't do any good! Then the penny droppped!

The outside temperature was around -12C (unseasonally cold in these parts). I think there was ice on the antenna (probably in it too!) and this was affecting the SWR. This morning, outside temperatures had risen and thawed a lot of the snow and ice. The hum has gone! So I'm sure that's what causes the problem.

Meanwhile, this morning, I heard Chris, G4CCC from near Reading calling CQ on 70.450MHz. Called him back and was surprised to hear him say that three people had come back to his CQ! Two of the others were in Surrey and barely audible up here in the frozen wastes of Oxfordshire - but it's great to hear more activity on 70Mhz.

Got a 70MHz FM set? Why not hook it up and try and make a contact or two?

Thursday, December 09, 2010

More real radio and Cyrillic morse

When I called Radcom VHF editor, David, G4ASR last weekend in the 144MHz AFS contest, it was fun when he replied "Good to see you doing real radio, Tim, don't bother with the other stuff!". Thanks for reading the blog, Dave!

There couldn't be anything much more 'real radio' than 3.5MHz CW, could there? Last night Julie was out at a WI meeting (oooh - I haven't mentioned her Etsy shop for a while - there are some lovely gifts for someone in your life - look out particularly for things she's made featuring our home-grown lavender) and I switched on the HF radio for some 'company' as some people would the TV...

Looking around the low-end of 80m, I tuned from station to station to get a sense of what the band was doing and stopped on a CW ragchew to see who it was. My CW's not quite as sharp as it used to be, but it's not bad and I don't miss much. But this QSO was getting me worried - I really couldn't understand much at all. Fortunately all became clear when the callsigns were sent - it was a UA4 talking to a UA1. Of course, they were using Cyrillic Morse - hence it seemed like some of the characters might be familiar, yet weren't! I always love to hear those Russian QSOs and on a winter's evening, it's surprising just how deep into the Asian continent you can hear if the band's quiet.

And so it was until an expedition landed in the vicinity (ZL8X?) and all hell broke loose. Then, it was time to go and make a coffee...

Sunday, December 05, 2010

Back on 70MHz FM

With the Es season just a distant memory, I've moved the 70MHz antenna from the FT847 onto the 70MHz FM rig, which is a converted Philips FM1000 PMR set. It seems to be working, though there are no QSOs to report just yet. I can hear the MB7UW packet node on 70.4875 some miles away and the GB3RAL beacon on 70.050 is loud! Test transmissions from the Wouxun handheld within the shack are loud too. So, hopefully there will be a QSO before long.

There's a net in Swindon on a Friday night now, 2000z, run by John, G4SRE - starting off on 70.450 and moving to 70.475 - so should be able to work some of those guys, and there's also some activity from Reading on, I think, a Tuesday night.

Friday, December 03, 2010

Ottawa D-STAR symposium resources online

Earlier in the week, I noticed from Alan, VA3STL's blog that the proceedings of the Ottawa D-STAR symposium were on-line.

Alsn did a nice write up on his blog and it's great to see that the slides from many of the presentations are online too.

I've not really had a chance to look at the presentations fully yet, but at a first glance they look great - I've learned plenty in the few slides I've looked at so far.

Thanks to Alan, VA3STL and also to the Ottawa Amateur Radio D-STAR group for this interesting resource.

Propagation: one of the fascinations of amateur radio

For me, and I'm sure I've said this before, one of the fascinations of radio is how how signals travel from one place to another; how signals can be strong one day and almost inaudible another. I find this true at both VHF and HF.

One of the pleasures I find on HF is to listen to a band that you think should be closed and see what's coming through. That's what happened the other night. I'd had a quick spin around 28MHz which wasn't doing anything at all (it was well after sunset) so I went down onto the bottom end of 14MHz.

The band was pretty quiet - but the great thing was that the only signals coming through were from several thousand miles away. First heard was a chirpy weak one, which turned out to be from Honduras, working into the USA. I listened to him for a while and tuned up and down the band a bit, only to find a Venezuelan station at good strength. He was also working into the USA.

Though I didn't get a chance to call, I'll bet a contact would have been possible and it's often fun to surprise people with a call from far away.

Even when you think the band is closed - have a listen!

Win 1000 QSL cards!

This is PROBABLY the only time you'll see QSL cards mentioned on this blog. It's really not my thing. BUT, I know it's important to a lot of radio amateurs and, as long as you don't force me to send bits of cardboard around the globe, then that's ok with me....

Over at where Matt, W1MST kindly syndicates my blog, you can win 1000 QSL cards from KB3IFH QSL cards. The cards look great!

So, why not enter the competition and try and win the QSLs? If you do, and you've worked me, you don't need to send me one, though. Thanks all the same. Good luck!


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