Experiments with an SDR4+ and a scanner refurb

Seems the holiday in early June broke the blogging momentum and unfortunately work commitments since and the stresses involved as a major project nears deployment have sapped my time and energy, so not had much to post.

Family commitments too have also eaten into my spare time not leaving me time or inclination to experiment. The FUNCube Dongle and the Ultra-cheap RTL-SDR have been unplugged for several weeks and I am ashamed to say most of my evenings have been sent slumped in front of the TV often nodding off to sleep rather than tinkering away.

That is not to say I have been completely idle! I have spent the last couple of weeks with a Cross Country Wireless SDR4+ receiver courtesy of my younger brother. For a while I have toyed with purchasing one after seeing them at last years Hamfest and have read some decent reviews. The SDR4+ is a HF Software Defined Radio covering 0.85 – 30MHz, the full specifications can be found on their website.

My brother shares a similar interest in radio, probably as he was forced to share a room with me when we were younger and I would subject him to listening to all sorts of strange signals late into the night! Well he decided to purchase one several weeks ago, but was frustrated when it didn’t seem to work. On one of visits to see my Mother I took a cursory look and couldn’t make it work either. To cut a long story short while he went away on holiday I borrowed the unit away to see if I could figure it out.

Following some experimentation and discussions with Chris Moulding on the Cross Country Wireless Yahoo Group turned out the problem was some dodgy USB ports and/or USB leads! The thread can be read at http://uk.groups.yahoo.com/group/cross_country_wireless/message/2136

I strung up a long random-length wire antenna in the loft and have managed to get some decent results on some bands, but interestingly very little on others, probably due to the lack of an ATU. But I have received lots of broadcast AM, some DRM (but not actually decoded) and buckets loads of Amateur transmissions, LSB/USB voice and Morse, RTTY and PSK31 from Europe, and decoded some HF-FAX. Sadly the SDR4+ will soon be off back to it’s rightful owner, but has certainly wetted my appetite.

I have also refurbished my Realistic PRO2022 scanner, as I posted back in 2010 this was my very first scanner and sadly was looking a little bit worse for years of wear. It is still functional, especially for listening to airband but the displays electro-luminescence back light had faded and it was looking a little grubby.

I had already replaced the backlight on my PRO2006, but this was a lot easier due to the display being easily accessible with the simple removal of the front panel, and the EL panel being on flying leads rather than soldered on to a PCB. 

I found a cheap supplier of a suitable EL panel on Ebay and quickly had the new one cut to size and fitted, giving a lovely new blue display.

 The next thing was to clean the grime and grease that was encrusted on the case and knobs, using a small amount of Clit-Bang degreaser and being very careful soon had the case looking almost as good as new!

A bit of a clean up and some repairs

The original plans for the weekend were thrown in to the air for a number of reasons. I spent most of Saturday with a saw, drill and screwdriver rebuilding part of the summerhouse in the garden and ferrying the old rotten parts and other garden waste to the local refuse tip!

Today (Sunday) I had the house to myself as the wife was off visiting her sister. As the weather has been absolutely atrocious, raining most of the day, I decided to have a bit of a clean up in the den. I’d noticed the fans in the main computer have been roaring under the slightest load recently and as I suspected the reason was the air intakes were blocked with dust and dog hair! While not quite as bad as these it was still pretty shocking as I do regularly check them.

As I had to pull them out from under the desk I decided to have a bit of a rearrange. While doing this I removed a redundant ethernet switch and an unused USB 1.1 hub, both were cheap far-eastern ones purchased many years ago. It now turns out they were a major source of interference on my scanners!

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The tidy computer centre (yes the external HD are sitting on a 1980 2001AD annual!)

One other task I achieved today was to replace the backlight on my Realistic PRO2006 scanner.

I purchase the PRO2006 from ebay about four/five years ago, I got it for less than £20 as it was advertised as for repair or spares. It was described as powering up with sound but because there was no display it couldn’t be operated.

When I got it (in it’s original box with manual) and opened it up it was obvious what was wrong as it appear to have spent most of it’s life in a shed or workshop, it was full of fine dust (I suspect from sanding wood) and this has blocked out the LCD display! It also had flecks of paint on the casing. The paint was thankfully emulsion and was easy to remove I just soaked the plastic case in warm water for a few hours. I stripped down the rest of the unit and removed the dust with a can of compressed air and a brush, other than that it worked perfectly!

One downside was the display backlight had faded, the backlight on many of the Realistic desktop scanners is an electro-luminescent panel and their output fades over time. Today I finally got around to replacing the panel, it isn’t as straightforward as it sounds as the spare part is no longer available but using the instructions found here I was able to replace it with a panel cut from a larger sheet purchased from Farnell.

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The display panel removed from the scanner with original backlight

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Original panel removed (top) and replacement panel cut to size (bottom)

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The new panel in all it’s glory!

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The only downside is from this angle you can just see the connector on the panel.

The backlight is now really bright, in fact I have had the ‘dimmer’ switch activated because it is so bright! I also have a Realistic PRO2022 and the backlight on that is fading too, it is nowhere near as bad as the PRO2006 was, but you can see the marked difference below.

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This shows the repaired PRO2006 compared to my PRO2022.

One other benefit of opening up the PRO2006 was I discovered a soldered connector on the shielding behind the front panel had come adrift. I have resoldered this and this has dramatically improved the reception and audio from the unit. Today has been a good day!