Some great movement on the txbpf project. All the vias and SM caps are installed, along with the other hardware which means the MB is now complete and ready to go. The photos below show the two completed boards after I had defluxed them in the workshop. I also made some impact on the filter boards. All the SM caps and relays are installed, so all I need to do is check the toroids, fit the high voltage caps and I am ready to start tuning. I have done one board and all the process took longer than expected – I reckon that completing all 12 boards will take most of next week’s build time, but it is progress indeed!
MB7UBP back on
I have been running an IGate in North London for some time, with the call sign MB7UBP using APRS4R running under OpenWRT on an Asus router. All has been fine and the system has needed little attention, until this weekend when the gate stopped reporting to the Internet.
I have logged into APRS4R and everything is running OK, but I couldn’t get the router to ping the WWW. I run a wired LAN to my radio shack (loft!) and the cables were firmly seated at both my ADSL router and the APRS box. This had stumped me for a while, until I realised that I was forced to cheat when wiring the APRS LAN cable. During installation I didn’t have a long enough cable to do the whole lot in a single run, so I made up two shorter cables, connected with a female back to back joiner. This joiner happens to be quite close to the main electrical switch to the shack and it seems that I managed to dislodge one Ethernet cable when I reached across to throw the switch on my way out. Doh! Anyhow, all is now fixed and I am back on the air.
That has taken me three days to work out, so my apologies to users who may have missed some functionality. The only good news is that the system was still active on RF and other local gates such as 2E0RNT and M0XDC probably picked up traffic for me in, albeit with an extra hop inserted.
As the shack is too cold at the moment to work on the remote project, I decided to move onto the next item on my list which I am calling TXBPF. At least 18 months ago Bob, 5B4AGN, designed and kitted a set of W3NQN bandpass filters that fit onto a custom motherboard. This looked like an opportunity that was too good to miss, so I bought two full kits which have sat on my to do list ever since. This week I finally made a real start!
The plan is to have a filter for each contest band which can be auto switched by the transceiver – perfect for the NFD run and spotting stations.
The first job was to wind the 48 toroidal inductors, half of which were either tri or quadrafilar. This took me most of the week and resulted in some sore fingers for this office-bound monkey. You can see one set of completed torroids below.....
The next job is to populate the motherboard and and the filter daughter boards with components. I managed to fit the 80 1206 SMD caps to one MB today, along with the 28 0805 caps to the daughter filter boards. I was pretty pleased with that for a couple of hours work. The photo below whows my workbench in the workshop at QRL. It was a longer than usual lunch :)
I don't often work with surface mount components, so I re-read GM3SEK's very helpful RADCOM guide before starting. I must admit that the brief session taught me a lot:
1) I have always relied on the solder to provide flux when soldering. The smaller solder I bought for SM work clearly doesn't have enough flux and my new flux pen, bought following GM3SEK's recommendation, makes all the difference. I am now a flux convert!
2) I often work under surgical microscopes and have over 15 years experience of manipulating things at high magnification. As a result this part of working with SMDs does not worry me at all and to start with I used a pair of old (but functional) electron microscopy forceps to manipulate the SM caps. I my professional life I find these good to tie 10/0 (0.07mm) sutures but found out today that they are too fine to stop the chips "pinging" across the workshop. A rummage in the lab turned up a pair of "rat tooth" forceps that did the job much better.
So, all in all, a lot of progress made. It seems I have lost a strip of 1203 caps, but being as I need to kit out a third set of boards that AGN offered without parts, I will pick up the missing caps in a Farnell order next week. Perhaps I'll treat myself to a real set of SM forceps at the same time to keep my new found momentum going.
Next job is to order my missing parts and complete the motherboards. That should take up most of next weeks building time.
The suburban radio ham faces a number of challenges and the most pressing for me at the moment is space. Over time I have traded bits of kit and built up a reasonable amount of quality hardware, but have never been able to set it up all at once to use it as I please. This creates frustration as I decide to have a go on a band or mode and I set up antennas, radios and amps but the inevitable trouble shooting when it doesn’t work first time drives me nuts. The birth of my son in June has reduced my time and also space – the room that housed my radio now contains a cot!
Since Matthew’s arrival, the radio shack has moved to the loft which is boiling in summer and freezing (literally at the moment) in winter. Apart from operator comfort, the ladder blocks part of the hall, meaning it really isn’t a convenient place at all. Some time ago I started to set up a remote shack, so that I could operate from anywhere in the house from my laptop. I used Bluetooth to transfer the audio and serial port servers to carry data back and forth to the radio. This worked OK, but ebay sourced kit proved to be unreliable. There are PC based systems out there and although I got one working it meant leaving a PC on at the radio end, which I didn’t want to do.
Just before Christmas I saw the remote rig interface advertised from Microbit (www.remoterig.com). This seems to answer many of my problems: streamed audio and serial control over one link with jitter free CW and the companion 1216E switch allows me to turn everything on and off over the network as well.
I bought a box (MKI, MKII was released 2 weeks later grrrr) and have just configured it to work over my LAN, learning a chunk more about networking in the process. I then realised that I would want to run the system from my new laptop that doesn’t have any serial ports. Faced with the possibility of having to hang a stack of converters of the laptop so that I could run N1MM I realised there was another way – using my MicroHam MKII interface to handle all of the rig control, CW generation (for contests), DVK and digi modes from a single USB port. Bingo! The only problem was that I had to design and build all of my own interface cables. I have done this over the last week for my FT-847 to get started on all bands easily. Whilst it is not that neat at the operator end, see the photo, it should be very effective. All I need to do now is attach the damn things and see if it works. The temperature here in London is well below freezing, so I won’t be sat in the loft doing this over the weekend, so I will try to drag a few bits down onto the kitchen table workbench to see how I get on...... Perhaps after Sarah and Matthew are safely tucked up in bed!
New year, same old promises – better diet more exercise, finish some of those projects that have been sat on the bench for ages. So, I have decided to do something about the radio ones. I have stacks to do:
1) Remote rig (www.remoterig.com ) the shack in the loft: interface cables need building then full installation and configuration made.
2) Finish ,well start, the W3NQN filter project that I bought the bits for 18 months ago (www.5b4agn.net)
3) Install new rotator and antenna stack on the house. I’ll wait for spring for that one.
4) Reinstall an HF antenna that works – the extended inverted L stinks on the higher bands
5) Build a PA for 4m so that I have legal limit on that band.
That’s the most pressing stuff. I also have some un built preamps, 6m PA project and APRS jobs to do. But let’s start here and see how I get on. I doubt anyone is reading this, but in any case I am making a public declaration so that I can be hung by my own petard!
A few notes on recent radio activity by Steve, M0BPQ.