Terminal Node Controllers / TNC’s…

Over the last few weeks I’ve been reading up on AX.25 and packet radio.  I really like the idea of being able to send and receive emails in the middle of nowhere, or when the power is out using amateur radio over HF, a car battery and a few bits and pieces.  One of the items I’ve picked up to help me do this is a Terminal Node Controller (TNC).  I know very little about packet radio, AX.25 and TNC’s in general, but I do remember looking at them when I was 14 thinking it was really cool that computers could talk to each other and you could log onto BBS’s over radio waves using them.

The TNC I’ve got seems to be a Advanced Electronic Applications, Inc.  PAKRATT 232, model PK-232MBX.  Its actually pictured on the Wikipedia entry, but I think the one I have is an earlier model because from what I’ve read AEA changed the LED’s to be mixed colours on later models and mine are all read.  If this is what I think it is, it seems to be a decent TNC with a built in mailbox.

Its not in perfect shape though.  Its missing some of the outer casing screws and the daughterboard doesn’t seem to have any screws in either.  The ROM is dated 19-7-1990, so I’ll presume that’s the American format for 19th July 1990 – if that’s the case its going to be pretty old.

I’ve dropped AEA an email to see if they can help me work out what TNC I’ve got, and if there are any ROM upgrades for it -  maybe if I order the ROM upgrade they can sort me out with some case screws.  Hopefully I’ll be able to get it working by the summer – just in time to take full advantage of the Advanced License which I intend to sit soon!

Intermediate Passed!

I’ve just got back from Preston Amateur Radio Society after sitting – and passing – the Intermediate exam!  As soon as my new call sign comes through I can take advantage of all the new terms of my license conditions :)

Overall the exam was a little more difficult than I was expecting, but I still got over 82%.  Now its time to start working towards the Advanced License.

Baofeng UV-3R+ and UV-5R+ Handheld Transceivers

Recently I decided I wanted a new hand held to play with.  I wanted something I could carry around without worrying about breaking it, so I ordered a Baofeng UV-3R+ from eBay.  This is a small form factor dual band (2M/70CM) that puts out 1W or 4W, it looked no bigger than a pack of cards so it seemed to fit the bill.

Shortly after ordering it I realized I hadn’t got the bundle with the USB programming cable, the radio’s are known for being difficult to program so I started looking for a USB programming cable.  It turns out that it was only a little bit more expensive to order a second radio and get the cable free, rather than order just the USB cable itself so I ended up ordering a Baofeng UV-5R+ too.

Both radio’s arrived (one from China and one from Hong Kong) and I’ve had time to use them.  The UV-3R+ arrived first, and I was initially quite impressed with it.  Its very small, light and does everything you need it to do (this is different from everything you want it to do).  The radio feels fairly cheap and is mostly plastic – you know you paid less than £40 for it, the control knob is very cheap feeling and I’d worry that it would be snapped off if I was lugging it around with me all day.  The speaker is very loud even on the lowest setting.  You can’t store channels with names which is the worst thing about it for me – if you put 30 repeaters in its memory your going to have to remember which one is in each channel.

The LED light seems bright enough and the broadcast FM radio works.  As with all Baofeng’s the menu system isn’t the easiest to use and I resorted to programming all the local repeaters with software (CHIRP) and had a quick play with Baofeng’s own software but didn’t think much to it.  Overall, the UV-3R+ works as it should, its very small, its very cheap but it does have its down sides.

Yaesu FT-60E and Baofeng UV-3R+ side by side.

The radio that surprised me the most is the UV-5R+.  This is much higher quality radio than the UV-3R+.  Almost everything about the radio is nice (in my opinion!).  The radio feels nice in your hand, the buttons have a nice click to them, the weight makes the radio feel like a good bit of equipment and the display has a quality look to it.  The bad points are the speaker doesn’t sound very high quality – its not terrible, but its not as good as the Yaesu FT-60E.  On a radio at this quality the broadcast FM, flash light options and alarm seem a bit gimicky, I would actually prefer if these options weren’t on the radio at all. The antenna socket is an female SMA so my existing antenna’s and adapters won’t work. The battery life seems very good so far, its been on for 3 days for around 12-18 hours each day with minimal TX and its still going strong.  Overall the radio isn’t as high quality as the Yaesu FT-60E, but its very close.  I am sure some proper radio-aficionados will know plenty of reasons why its not a great radio and I’m sure they are correct, but what you can’t get away from is the radio costs less than £40 and is worth every penny.

Yaesu FT-60E and Baofeng UV-5R+ side by side.

I’ve also bought an Diamond SRH805S stubby antenna (all the pictures here have this antenna on, its not the standard one that comes with the Baofengs) for the UV-5R+ and its fits perfectly  with that in place the UV-5R+ its going to become my carry anywhere radio.  I’ll probably try and use the UV-3R+ as some sort of APRS station.  I feel a bit sorry for my Yaesu now, its a great radio but I don’t want to damage it lugging it around in a bag, the SRH805S antenna I got for it doesn’t have a flush fitting so its really just going to be a stay at home handie for now!

WSPR #2

I haven’t played around with WSPR for a while, so this morning while I was revising for my Intermediate Exam I thought I’d leave WSPR running on 20M.  I’m much more comfortable with the Yaesu FT-817ND and LDG Z-817 autotuner now, and understand the differences between long and short button presses, so I am able to keep my SWR ald ALC nice and low.

The only issue I am having is getting the RX noise dB correct.  On the WSPR chat page people have told me it should be as close to 0dB as possible, but the only way I can close is to turn the RX down on my SignaLink USB and when I do that I don’t hear anyone. If I have it around 25, I hear plenty, but the RX Noise bar is red!  Anyway take a look at the propagation map for this morning.

I think the next digital mode I’m going to look at is JT65A.  From the little I have read about this, it seems like another WSPR-like piece of software.

14.195MHz

Wow! I just had the “pleasure” of listening to a DX conversation between a German station and an Italian station on 14.195MHz.  It appears that IT9RYH (Nino) has an agenda that most other stations don’t understand or agree with.  I’m still new to the hobby so I’ve not really got much of an opinion on it, but either way it was an interesting conversation.

WSPR

I’ve been playing around with WSPR over the last few evenings with my new Yaesu FT-817ND.  WSPR stands for Weak Signal Propagation Reporter.  You basically send low power signals out over HF and some software on another persons computer picks these signals up and decodes them so you can see how far your signals getting. I’ve finally made my first trans-Atlantic contact.  Station W3HH in Florida could hear my transmissions at 5W from the UK.

It took me quite a bit of reading to get WSPR setup correctly, so I thought I’d write a blog post on how to do it in the future.  Some of the options and settings you need to choose for both the software on the computer and the radio were difficult to work out.