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Saturday, 31 December 2011

Tuning - with less noise!


For some time I have been using an LDG Electronics AutoTuner here in the shack. It's been an OK experience and the ability to change bands and then have the tuner sense the RF frequency and auto adjust itself back to the previously stored settings for antenna and band appealed greatly. Set it up once and never touch it again - perfect!

The theory was fine, but it didn't quite work in practise. The device never quite matched the antennas correctly - I always found it necessary to tweak the automatically chosen settings and then store them manually plus on most bands I couldn't quite get a 1:1 match. My biggest concern with the unit was that the SWR reading on the tuner itself didn't ever match the readings at the radio or with the separate meter I have here. The net result was that I was tuning for the best match read by the radio, which was normally quite a miss-match according to the tuner.

Anyhow, to cut a long story short, I have purchased a MFJ roller coaster based tuner:

Looking at this picture worried me a little. There very much looks like there is a dent in the top of the unit! However it's completely invisible unless taken by a camera with a flash but I should probably consider reporting this back to the supplier.

Anyhow, using the device as a tuner seems extremely easy. MFJ tend to have a bad reputation and are often called "Mighty Fine Junk"; however, my experience is all good. This tuner does exactly what is says on the tin. I've completed some tuning charts which I will try and print out and place somewhere near the unit itself in the shack.

The cat has taken on a whole new degree of madness; he has now taken to sleeping in the cover of my 'scope on a high up shelf in the shack:

I'll keep you posted on the tuner, looks OK though, egh?

Thursday, 29 December 2011

It must be Christmas

Well, not much going on here; just been playing Radio and generally taking things easy.

I made a visit to the post Christmas sales and came home with a laptop which is now interfaced to the FT857 via the homebrew device I was making earlier:

That is enabling me to leave the laptop running WSPR whilst all the other electronics are shut down - except the FT857, of course.

Very neat laptop, got one of these new fangled Intel i5 processors and is running 64bit Windows 7 - all reasonably well priced and more importantly low power consumption.

I used to leave both PCs running in the shack, but more recently have taken to shutting them down - primarily to conserve power. But now I genuinely find that the shack is rather cold in a morning so I'm turning the heat on - not much of an energy saving!

The shack is looking quite tidy right now, I've even added yet more shelves to create more space in this tardis I spend my time inside:

I need to get outside and look at the Windom antenna again:

because the SWR on the antenna is bouncing in windy conditions (again). I suspect it might just be too close to the other metal objects and when it moves around it's either touching the mast thats holding the 6m beam in the air or actually touching the antenna itself. Only time will tell.

The Geddy cat has many places he could chose to sleep; he has two proper cat beds, theres also four people beds in the house, plus a choice of sofas, chairs et cetera. He does, however, prefer to sleep on the clean washing as it waits for the ironing fairy to pop round:

Damn crazy cat!

Wednesday, 21 December 2011

Three Soundcards - No Problem!


following the last escapade with exploding USB soundcard devices, I purchased an alternative from a local store. This time is was a staggering £10.

I hooked it all up and everything seemed to be working fine; I made a few minor adjustments to the audio attenuation levels going into the soundcard mic input, but nothing unusual.

So now we have the shack looking like this:

And the FT-857 is happily WSPering away:

Given that its quite early on a dull winters day here in Belper, this is with the output power set at 10W:

And here, as a change from the mandatory cat picture, is my Bird of Paradise, grown by me from seed and in flower:

Fantastic, hugh?

Sunday, 18 December 2011

Three Soundcards - No, you must be kidding?

Well, today has been a rather perplexing day.

I've been making a digital mode interface for my FT-857; I want to let it sit here in the shack WSPR'ing away. For WSPR see:

So the construction of the interface was very simple, I used some of the building blocks here, this is a great site run by Ernie, WM2U:

And the interface looks like this:

So, the Windows 7 PC I have here (It Runs Win 7 Ultimate), has on-board sound which is interfaced to my digital modes box which switches between my FT-847, FT-950 and FT-2000:

Then there is a high spec PC soundcard which is used for the SDR receiver:

And now (as you will see from the photo above) I am planning to use a USB soundcard for interfacing to the FT-857 I have here.

All was going great, the soundard installed fine, I was receiving WSPR on 20M, I tried the PTT circuit which was also working great. Then I put the software into TX and everything stopped after about a ms of audio out. I then spotted that the USB soundcard was red hot.... I happened to have two of these USB devices, so I tried the other one. That one got even hotter.....

I guess this is what you can expect from an ebay purchase that cost me something like £1.20 including delivery.

You live and learn... I need an alternative third soundcard.

I'll keep you posted.

Fun, egh?

Sunday, 11 December 2011

It's Just Been Far Tooooo Long...


The job has been getting quite seriously in the way of my play time recently. As inconvenient as it is, I guess there wouldn't be much playtime without the job!

First thing to report is that myself and my mate Vince, G0ORC, took the trek down to ML&S in Surrey for their open day, there site is here:

Vince bought all sorts of stuff including a tube linear; the net result is that I have bought his old solid state Almeritron linear from him as his purchase was a replacement:

It looks like this:

And there's a very heavy matching 50V PSU to go with it:

So the acquisition of this linear has triggered yet another "I haven't got enough space" session in the shack. I've ended up bodging a new shelf to put this on:

So it's all kind of fitted OK.

The second thing to report is that when I was at the ML&S open day, I purchased a replacement for my wire Windom antenna. I picked up a Radio Works Carolina Windom 80 Compact:

What I failed to spot was that the "droop" on the folded element is 15 feet! It's not drawn to scale at all and I ended up in a total pickle.

To start with the existing Windom had got a bit wet in the coax connections; the entire length of coax was shot - how it was working in beyond me - this picture is of the shack end of the line, some 15-20m from where the water is getting in:

So, duff coax plus I managed to destroy the existing antennas line isolator (that's the bit at the bottom of the vertical resonating part) when I unscrewed the connector. 
I now had the existing antenna broken, the new antenna knotted in the trees and clearly never going to fit (with the droops) into my back garden and generally in a total muddle.

I ended up ordering a Windom 80 Special from Walters & Stanton plc:

And finally, after much cursing in the dark after work on a few evenings this week, it's finally up. Just to add to my pain I added a pulley to the pole so (I thought) I wouldn't have to take the whole thing down just to get at the wire antenna. Hah! The pulley and pole acted like a great lever and turned the vertical pole into a banana! Down in all had to come again:

You can just see the matching transformer on the Windom in the picture above. This was after I had adjusted the pulley arm to be more central to the whole thing.

The house is kind of looking like this now, how I don't get complaints I am not too sure:

So all in all, a rather expensive exercise. New antennas (2) and new coax was about £400 all told! I suppose the old antenna had been with me since the mid 90s so it didn't really owe me anything.

Here's the mandatory cat picture:

All looking good, though, egh?