DVB Dongle

I have been reading quite a bit lately both on the Web and in the various radio magazines about the use of cheap USB digital TV dongles as VHF/UHF SDR receivers. Whilst browsing Amazon the other week, looking for a birthday gift I noticed that they had suitable USB dongles for around £11. At this price I could not resist. Well the TV dongle arrived yesterday. After a few false starts I have managed to get it to work with the "SDR Sharp" software. So far I am just using the tiny vertical antenna that came with it but I have managed to receive some local FM broadcast stations. I have an antenna adaptor lead for the dongle so will see if I can sort out a better antenna. For the very modest cost it has to be worth experimenting with this little unit.

Murphy's Law!

Operating from the "alternative" location this evening. The pro whip  got me a couple of European QSOs (ZA and E73) on 17 metres.Heard a few stateside stations too. 40 metres has S9 noise here tonight, may be band conditions but this is a noisier location than my home QTH. I had the idea to listen to my remote SDR receiver at home using my netbook here to see if I could hear my own signal. No luck though as the RF from the TS450 is knocking out the wi-fi connection on the netbook!

Alternative location

This weekend whilst visiting the YL I took my Kenwood TS450 along and set up an HF station using the portable "Buddistick" antenna. Operating time was very limited  as it wouldn't be polite to spent my time on the radio when I am supposed to be spending time with the YL, but I did manage an hour or two of radio time over the weekend!
Additionally  the antenna had to be placed in a corner of the small garden, out of the way of inquisitive young children! Sadly HF conditions were not too good  but I did manage a QSO on 40 metres SSB into Northern Ireland as well as a chat to a more local GW station. The Buddistick does work but its quite difficult to tune and changing bands  means going out to the antenna to move a tapping point on the coil.CW is your friend with this antenna , I have always found SSB contacts with it quite difficult. It is an easily portable antenna but its small size has limitations.

Buddistick in position at the alternative location

The "Alternative" shack. (The "Stuff" behind the radio isnt mine by the way!)

As an alternative to the Buddistick for portable work,I have recently purchased a Pro-Whip portable antenna. This is basically a glassfibre fishing pole, 6 metres high with a wire running up inside it, a 9:1 Unun at the base with a wire counterpoise. I have only had time to briefly set up this antnena at the weekend but first impressions are quite good. It is very easy to deploy, tunes from 80-10 metres using just the internal ATU in the TS450 and seems livelier than the Buddistick. I hope to update the blog in the coming weeks with my experience of the Pro-Whip.

Pro-Whip on test in my garden

Out with the old

Well the old, rather poor quality Sirio Boot (trunk) antenna mount on my car finally gave up a few weeks back. I used this mount for my VHF antenna. The Coax connection came adrift inside the mount. I had been meaning to change it for some time anyway so no problem. Actually there was a problem. Not only was the mount rusted on top and looking pretty nasty, the allen screws underneath which grip the bottom of the boot lip had rusted solid! Nothing would shift them! The answer? My trusty hacksaw- I had to carefully cut the mount of. Lukily I managed to avoid damaging the car.
I replaced the mount with an unbranded one obtained from Ebay, model number MB400. It looks a lot sturdier than the Sirio but time well tell. In any event it is unlikely to last as long as the Diamond mount holding my HF mobile whip, that must be around 20 years old. Those mounts are around £60 new though so for now I will try the MB400!!

Up Up and Away...............

Today I finally removed the Wellbrook receive loop which has been hanging in the shack window for the last 18 months. It worked there, better than I thought it would but it was well down in terms of signal strength compared to my wire doublet.
It is now on top of the pole at the end of my garden at a height of 20 feet or so and in the clear. I havent had much chance to test it but it seems to work better up there but not THAT much better. The Western HF 10 doublet is a far better receive antenna on all bands other than top band and medium wave. Still given the size of the loop it is quite an impressive performer.

Surprise DX!

At home a little earlier than usual this afternoon I decided to take an hour out in the shack. 15 metres seemed quite active so I set up the FT1000MP on PSK31 and worked UR4UM  which confirmed everything was working OK since i changed soundcards on this machine.
I left the rig monitoring the bands whilst I pottered about in the shack. Nothing unusual on the screen, mainly European stations with the occasional Stateside signal to be seen. Then I noticed HI8CSS calling CQ from Dominican Republic. I called him, not expecting a reply as surely there would be a pile up and I was running 20 watts into my doublet. He came back to me instantly with a 599 report and I had 100% copy on him. So a new country for me and quite a shock too!

Antenna maintenance

Over the past few days or so I had noticed that the performance of my HF wire antenna (the Western HF 10) had changed. The SWR was higher than usual where it was resonant on parts of 80, 20 and 10 metres the SWR was now 3:1. The rigs auto ATU still tuned it ok on most bands but the receive seemed a little down too.
A physical inspection of the antenna itself showed nothing obviously wrong. I then disconnected the Coax feed at the antenna end and replaced the antenna with a dummy load. The dummy load showed 3:1 SWR. So the fault was in the coax or maybe the PL259 plug. Not surprising perhaps in view of the very heavy rain and substantial snowfall we have had here over the past month.
So out came the soldering iron and off came the PL259.

You may just be able to make out the corrosion on the plug in the picture, the body of the plug also looked a little bit tarnished. It seems water had found its way in even though the plug had been given a good covering with self amalgamating tape. Luckily trimming the coax back a few centimetres showed that water had not got that far. A new plug was soldered on and reconnecting, weatherproofed as much as possible and the antenna was back to normal! Thankfully an easy fix.