I'd Get Annoyed - If I Actually Cared

Well,

Been doing a bit of JT65ing over the past few days, using the callsign A71A from QARS:

This is my friend Ali, A71BZ, I've been trying to get over to him and others the benefits and usage of low power digital modes. It seems, however, when you live in the desert, have oodles of space for antennas and can run power without anyone even noticing, SSB has great appeal....

This is the simple setup I have been using for JT65, on the left of the FT-2000 is a gigawatt rated ATU, in front of that is the remote control for a 2K amplifier from Acom, and above the ATU is a bandpass filter box of some kind. This stuff is used when they have two stations running in the same room at the same time with antennas not very far apart. How well this works is rather dubious as the preamp in the FT-2000 is clearly destroyed - running in the setting IPO results in far stronger signals that using Amp-1 or Amp-2. All is clearly not well inside the radio.

Anyhow, my 20W on JT65 is leading to signals all over Europe and as far the other direction as Japan and China. Something is working.

Now, here's the problem. When I am in QSO with someone in JT65, I really don't expect other stations to start calling me on top of the station I'm working while I am mid QSO- there's a fixed set of exchanges in JT65... as any JT65 operator will know. I understand that the call is probably a new country for most in that mode but....

Do I need to say more - this applies as much to digital modes as any other mode:

I kind of though that the digital boys were better behaved - how wrong I was.

Not done much from the apartment yet:

Being on the 21st floor is likely to have advantages RF wise - it's not so clever when the wind is extreme and there's sandstorms outside. Time will tell...

Bad news though, egh?

Wow, that's a long way down...

Well,

I'm back in A71 land and have finally got the appropriate approvals to use A71/G0MGX whilst in region. This is good news indeed.

To coincide with the timely arrival of this approval I have also moved into an apartment within the centre of Doha. This will be my residence whilst I am in this part of the world between now and the end of the year.  I already know where the buddypole will be sited, it's a long way down though:

This is the view that the buddypole will have, it's kind of looking West:

So, all I need now is some equipment. I'm planning to bring my FT-450 and Buddypole with me next time I travel back here.

I've also sent the appropriate evidence to the ARRL and have already received the certificate for my A71 callsign for LOTW:

Interesting times, egh?

A what-un? ah, A Balun!

Well

Whilst musing about being able to run SO2V or SO2R back here:

http://g0mgx.blogspot.co.uk/2013/04/so2v-so2-what-ah-2-vfos.html

there are quite a few things to consider. If I am going to operate with 2 radios at the same time, the most important factor will be protecting the radio in receive from the high RF generated by the radio in transmit - this could result in some very expensive damage if not catered for correctly - more on this later.

The other thing I need to accomplish is a second antenna for the higher bands. Lets say I want to run on 20M and 15M at the same time, clearly I can use the MA5B on one radio, but I don't currently have a second antenna for either of these bands. The simplest solution (as very much a starter for 10) is to cut and hang up a simple common multiband antenna - a G5RV. I've cut one using some hard drawn copper wire I had here, some 450 ohm ladder line and a commercial balun...... hence the confusion and lack of understanding.

I've always been bothered by baluns - what do they do and how do they do it? Whats the difference between a current balun and a voltage balun - whats a 4:1 balun for? Whats a 9:1 balun for? Why don't I just go out more and not worry?

Over the coming weeks I plan to run some experiments to answer these questions, to run some tests against a commercial 1:1 balun, and to construct some baluns for myself and see what they actually do.

So, starting with the newly strung G5RV which I've included a commercial balun between the 450 ohm feedline and the coax to the shack, I see this with my newfangled antenna analyser thingamabob:

Now, I only plan to really use this antenna connected to a second radio, but as a starter for 10, the antenna looks like it's OK ish. As a quick test (clearly the SWR on my dummy load will be better!) I left the antenna and radio WSPRing on 30M last night:

So, I conclude that the antenna radiates and it looks like I can transmit a signal using it.... so it's not just a dummy load. This is a good start.

So, the next project will be some kind of band stop filters for the radios so certain radios can only be used on certain bands - this should allow me to experiment with SO2R in an RTTY contest.

Now, back to baluns.... A balun should be used where we go from a balanced arrangement (e.g. a dipole) to an unbalanced arrangement (e.g. coax cable). I would therefore expect that the output of the two balanced ports of a balun would be out of phase with each other when compared to the ground point of the input port. Here I am feeding a 10MHz signal into a commercial balun and measuring the two terminals of the balanced output:

So, the yellow and the blue (please ignore amplitude) are the two output ports and the green is the sum of the two signals.... they look to me to be about 45 degrees out of phase - this is not what I was expecting at all! I thought they would be 180 degrees out of phase such that the sum of the two was as close to zero as makes no odds.

Unfortunately (or fortunately, depending on how you look at it), I'm heading back to A71 land again today.... I'll be picking this up in about two weeks when I get back.

I'd like to hear from anyone who understands the 'scope output above though, confusing - egh?

RTTYing in A71 Land

Well,

Its been snowing hard in the UK (so I understand), but I'm stuck in A71 land this weekend....

The Qatar Amateur Radio Society were doing a stall at an exhibition recently, I called by to see them, here's the set up:

I've actually spent some time at the QARS main site today, you may remember I visited them a while ago:

http://g0mgx.blogspot.co.uk/2013/02/a7-land-a71a-ah-qatar.html

I've been running RTTY using one of their FT-2000s. You may recall I made an interface for my FT-450 a while back:

http://g0mgx.blogspot.co.uk/2013/01/hows-interfacing.html

Well, here it is on top of the FT-2000 - plus an adapter for the rig end of the cables:

So been running on 20M RTTY today with the callsign A71A. Been quite hard work as at times there were many stations calling, but no single signal decoding, I guess I perhaps need to consider working split next time.

Fun though, egh?

A7 Land, A71A - Ah, Qatar!

Well,

As I mentioned a while ago, I am now spending some of my time in A7 land. Been here today:

Amazing welcome and a really impressive place. I'm hoping that I will be able to get A71/G0MGX so I can operate here. There is talk of a reciprocal licensing agreement between the UK and Qatar; I've given over copies of my license and various other bits and pieces and the guys at QARS are going to progress the application for me.

Here are a couple of other shots from A71A:

And this is the top of a recently imported tower from Germany:

This is the bottom of an identical tower (they bought two):

So, I have to be patient, but I am confident that the guys will do all they can to help me.

Wonderful, egh?