Winterising Aerials For The Harsh Weather Ahead

John (M1FEL) and I, a week ago, were taking down the main aerial pole in order to re-attach the full-size Windom HF Aerial ~ as the rope had finally perished.  It was last checked a year ago!

The main HF Windom attaches to the pole seen on the right-hand side

I took the opportunity to winterise the folded 4m band (70MHz) dipole, which you can see reaching out to the left of the main HF pole, to make sure that the internal balun would not see any ingress of water.  All the connections were great from last year but, to make sure, I replaced the rubberised self-amalgamating tape and cable ties.  At the same time, I attached a stainless steel 'Discone' aerial on top of the main HF pole.  Now I can hear the controller (and not just the aircraft overhead) at Lydd Airport & also at Laschenden (Headcorn) aerodrome.  Great improvement!


If you notice, there are other poles sticking up above the small flat roof that my wife & I have.  Looking at the white fibreglass aerial 'nearest' the TV aerial on the chimney, you can see my main 2m (145MHz) & 70cms (433MHz) aerial: 

X510HDN Base Antenna
Specifications:
Band:	2m/70cm
Element Phasing:	3-5/8l/8-5/8l
Gain (dB):	8.3/11.7
Watts:	330 (2m) / 250 (70cm)
Connector:	Type-N
Weight:	5 lbs.
Length:	17.2'
Max Wind Resistance:	90 MPH

It is really an effective aerial and the coverage is phenomenal from up here!  I am really pleased with this.

X510HDN Base Antenna is the white 'stick' on the right hand side.

The pole to the left of the X510HDN holds a 10m (28>29MHz) fibreglass aerial for DX and Ground Wave working.  When conditions are right, I use this aerial for 10m FM DX (long distance) contacts.  Very efficient, with no measurable reflective power ~ so all power from the radio is effectively radiated from the aerial itself.  All feeder cable to my aerials are 'top-notch' military UHF (Ultra High Frequency) 'spec' ~ which is overkill for the 10m band, but there is minimal loss through the cable!

Finally, the pole on the left-hand side of the photo above shows a 3-element 6m (50MHz) horizontal beam, on top of a rotator, allowing me to turn the aerial to face DX stations around the World.  Above it is a V2000A Tri-band Base Antenna:

Specifications:
Bands:	6m/2m/70cm
Frequency (MHz):	52-54/144-148/440-450
Gain:	2.15dBi/6.2dB/8.4dB
Impedance (nominal):	50W
VSWR:	1.5:1 (typical)
Power Rating:	150 watts
Element Phasing:	1/2l/2-5/8l/4-5/8l
Max Wind Rating:	112 m.p.h.
Mast Dia. Acceptance:	1.2 to 2.4 inches
Length/Weight	8.3 ft./2.6 lbs.
Connector:	SO-239 Female

This, again, is a very efficient aerial ~ one that I use for 'local' nattering on 6m / 2m / 70cms!

Hanging just this side of the Kent Cobnut Tree is the white centre balun of the HF Windom Aerial.

The other end of the Windom aerial is held aloft by the use of an ex-military high-grade aluminium telescopic mast.

The telescopic pole can be seen extended just beyond the white reclining seat.

You can see the radiating element, the vertical cable running down from the large white balun held aloft, running towards the pump house and then into the main property.  High-grade coaxial cable, again, but the distance from the 'Shack' (Radio Room) to the main feed point is only 30 feet. Nothing for the HF ('Short Wave') bands!


So there we have it!  Ready for the Winter ahead!  Here's hoping for some choice contacts on the Amateur Radio bands.

Shackbox Air ~ Linux Operating System for Radio Amateurs

So why Linux?  Why Shackbox Air?

The Data Operating Area Of My Amateur Radio Room ("Shack")

For those of you interested in computers and operating systems, I first started using Linux after a couple of years playing with IBM's OS2 operating system ~ way back, in computer terms, to about 1990 ..... frightening!

I started with SUSE Linux after OS2 stopped being supported (a missed opportunity by IBM, in my view  ~ just look at Apple now!), version 3 I seem to recall???  In any case, from the early 1990s I have been running Linux somewhere in the house ~ usually in more than one place.  Who said "Geek!" ???

http://shackbox.net/ is the latest Linux software to be tried in my "shack" (radio room) ~ which links two of my hobbies together: Amateur Radio and Computing.

Linux is far more stable than windows.  Apple know this, which is why their OS (operating system) has been developed from earlier versions of the software you can get for FREE ~ namely Linux!!  There are several 'flavours' of Linux, in much the same way as there are many car manufacturers (automobile for my American readers) .

The point about Linux, however, in all its guises, is that they all operate using the same main engine.  They may be tweaked and tuned slightly differently, with many of them looking cosmetically different (colours and the type of user interface are two examples), but they all work in a very similar fashion.  More importantly, they are all FREE !!!!

Another benefit is that older PCs can run more efficiently on Linux than they can using Windows ~ as the specification needed to run a fast and efficient Linux system is not as great as for the Windows OS family.  This means that you can breathe new life into an ageing machine, have more for your Buck so to speak, and save the planet at the same time!  A Win Win Win situation!

For me, it means that I don't have to 'tie-up' an up-to-date computer with tasks that can be easily handled by an older PC running Linux.  With all the programs being free (Open Source) and with such a great selection of written, tried and tested software available, it is just a 'no-brainer' in my book.

So that is why I use Linux in my Radio Room ("Shack"):

A Huge Collection Of Amateur Radio Software Is Already Included

Clicking On The Antenna Design Folder Shows Many Tools Available ~ Included As Standard!

There Are Plenty Of Programs Available Within The Electronics Folder As Well

This version of Linux also contains the usual 'Office', 'Graphics' and other common Linux programs.

Until next time, when I will develop the reasons why a FREE Linux OS may benefit you.

Change of Aerial and repainting mobile mount

A couple of days ago I received my new Diamond NR-790 Mobile aerial (Antenna for my USA readers) to replace the one I borrowed from my friend John (M1FEL).

Diamond NR-790 on car

You can see that this is the Mark II model ~ now using two heavy-weight closed coils.  The 2m band (145 MHz) sees the aerial as a 6/8th wave device (giving 3.7 dBi @ maximum of 300W power out of the radio) whilst the 70cms band (433 MHz) identifies the aerial as 3*5/8th wave device (giving 6.4 dBi @ maximum of 250W power out of the radio).  The aerial is able to handle more than I require, but it is substantially made and has already given fantastic results (see below).

The base below the black 'collar' is much improved

The photo above shows the lower part of the aerial.  Between the mount, i.e. bottom of the aerial, and the first black collar is an important part of this aerial's success: it is a built-in 'ground-plane' ~ ensuring that the aerial is really efficient when it comes to 'matching' the frequency in use.  This section is much larger than the Mark I version ~ probably to handle the extra power ~ but also because the matching has been improved.  The aerial performs as least as well as the Mark I, maybe better?

Painted aerial mount

If you look at an earlier post, you can see that the aerial mount had to be modified ~ leaving it a mixture of black & silver, with a touch of bronze!  I'm not usually worried about looks but, on this occasion, I thought I would paint it all black, using enamel bought from a local shop.

Needless to say, they did not have black!  Henry Ford would be turning in his grave, I thought, but then I saw a pot of red enamel.  The rest you can see for yourself!  I think it looks better ~ even though I have to clean the red enamel off the wire later!

As for the efficiency of the aerial?  Using 5 Watts of power from the radio, I can talk for miles on 2m (145MHz band) ~ not using a repeater I quickly add ~ and I had a similar reaction when using 5W on 70cms (433MHz band), despite going into dips, under tunnels of trees, etc.  Quite amazing!

John (M1FEL) and I will continue to carry out tests on the efficiency of the aerial over the next few days.  Our test for tomorrow will be to see how far we can work each other using 5W on 433.375MHz.  

More anon............ so watch this space!