Monday, 4 April 2016

Updated Ramblings

My experiences of setting up a node for AllStar have prompted a fair bit of testing and a little code writing, and my latest project - a mobile hotspot. I downloaded and installed the Asterisk image and wrote that to a 16 gig SanDisk micro SD card and uploaded it to my Raspberry Pi2. Software sorted, I then drove a 90 mile round trip to collect a modified Baofeng 888, hard wired to a modified sound fob, which interfaces with the Pi. Hardware sorted. Initially the Pi has to be connected via an ether net cable and Putty (an SSH client) is used to set up the configuration to run the node. All fine so far. Then I had to go into the network configuration file to find the wireless connection to my mobile phone hotspot. After countless visits to Google to find out how to get into the config files, I eventually managed to set up the connection, unplugged the ethernet cable and did a re-boot of the Pi. On re-booting, the Pi did indeed find my phone and I then proceeded to set up the audio on the node. Having set everything up I retired to my much missed bed and left the mobile installation for the next day. Using a 12V to 4.5V adaptor to power the BF-888 and a 2A USB supply for the Pi, I found a convenient spot in the dashboard to install the Pi and the interface and another spot to locate the radio. On test, the initial verdict was that it was all working as it should and I undertook a journey to test the mobile capability. I used the dual band mobile radio installed in my car to activate the node and was informed that there was massive over-deviation. So, I switched to another Baofeng handheld and tried again, this time ensuring that narrow deviation was selected. One user reported my audio as "too loud", another said "too quiet", yet another said "quiet and then loud" and a final operator described it as "just right" - quite which report was accurate is debatable but it seems that individual opinions vary greatly.

Problems continue to plague the DV4 Mini - this time it's software issues. I recently got hold of a Windows tablet, to be able to use the dongle when away, and I downloaded and installed the software and it worked perfectly - in fact it worked better than with the laptop, perhaps due to the tablet having a quad core processor, whereas the laptop only has a dual core. All worked well for a couple of weeks until the software started causing issues. When booted, the DV4 control software initiates in DStar mode, when changing to DMR mode, an exception occurs which closes DV Serial and connection to the dongle is lost. A look on the official software download site proved fruitless as all previous versions of the software had been removed, so rolling back the software version was out. I can't be bothered with it at the moment, so it will remain where it is until I can forgive it's shortcomings. Recent developments with the DVMega project have resulted in a software update which enables connection to the DMR network, using Bluespot software. I think this will be my preferred method of connection in future. In the meantime, I can still use DMR in the car, by utilising the facilities provided by GB7RR - this entails a short drive (about half a mile from home) but that isn't really a big deal to me.

I have experienced a noticeable increase in the VSWR with my X510 Collinear. I initially suspected the feeder but I think there might have been an amount of water ingress into the antenna. With the high winds, the aerial has swayed about a little, and I wonder if that movement has allowed the water in. I will take it down at the weekend and replace it with my X50 - this time on a six metre pole on the T&K brackets on the side of the house. I would think that the shorter length will eliminate any flexing in the wind and, although the antenna has less gain, the increased height shoud improve performance. I will replace the feeder as a matter of course, so I will hopefully have a correctly functioning V/UHF set up again.

The latest radio to be added to the collection is another Kenwood TM-G707, bought second hand from a local amateur for a very reasonable price. I already have one, indoors in the shack and when this new (to me) one came up I jumped at the chance to install it in the car. Receive audio is superb, as is transmit, and I find Kenwood equipment to be particularly well suited for mobile installation.

I really need to stop spending on radio for a while - I could do with saving up for a Yaesu FT-817 for portable use in the upcoming Summer season - I still have the Ampro 40m Whip.

Well, I'll leave it there and until next time - 73 de 2E0ENN

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