Tuesday 21 July 2015

Amateur Radio Parity Act

Regular readers will know of my general disgruntlement with the Radio Society of Great Britain (RSGB).  Top of my moan list was that the RSGB , through its own admission on several occasions, has never particularly campaigned for improvements to permitted developments within planning legislation.


As a result, the RSGB's planning service is reduced to simply telling members what the law on antennas is - which you can anyway find for free online at the Planning Portal - and writing the odd support letter to councils (which, coming from a hobby society, can be expected to have very little impact.)

Contrast this, then, with the current, high-profile campaign by the ARRL and US-based hams in general to support the Amateur Radio Parity Act.  This Act will see amateur radio stations no longer subject to neighbour hostility and prejudice that has led to a nationwide proliferation of House Owner Associations simply saying "no antennas here."  In every real sense, it has been a rapidly-growing system that was bringing the hobby to its knees, often being so strictly implemented that even an essentially invisible wire around a balcony could bring action against the owner.

Now, amateur operators look set to be granted the same right to develop their land in respect of antennas as any other emergency user.  Whilst there is no guarantee of success, the notion, campaign and support is really a positive story for amateur radio, and one that leaves the RSGB, yet again, lagging well behind, content simply to concern itself with the interests of hardcore DX clubs, committee urchins, and the bah-humbug elderly who have long lost sight of how modern Britain works against its own people.

Well done, the ARRL!  Well done, the US of A!
“What if their parents have bought houses in neighborhoods with deed restrictions prohibiting antennas?” she speculated. “Those kids’ interest in ham radio gained from school, Scouts, or family friends will have no way to blossom into the life-changing experience of being radio amateurs.” - See more at: http://www.kingscountyradioclub.com/the-amateur-radio-parity-act-of-2015-politicians-do-listen-arrl-president-says/#sthash.OlRKC5To.dpuf
“What if their parents have bought houses in neighborhoods with deed restrictions prohibiting antennas?” she speculated. “Those kids’ interest in ham radio gained from school, Scouts, or family friends will have no way to blossom into the life-changing experience of being radio amateurs.” - See more at: http://www.kingscountyradioclub.com/the-amateur-radio-parity-act-of-2015-politicians-do-listen-arrl-president-says/#sthash.OlRKC5To.dpuf

Thursday 9 July 2015

SDR Receiver

A mate of mine bought a new Elad SDR receiver the other day.  Lucky him!  I'm not much into simply listening, but that's not to say I don't have any interest in it.

Nice design.  How does the entry-level version of Elad SDR compare, at £500, against a £37 dingle-type SDR?


I've been thinking about one of those FunCube or Watson dongles for a couple of years.  But the price of about £100 - £150 was putting me off.

A quick search online revealed SDR receivers on Amazon and Ebay going for about £37.  That's more like it, and all-too-typical of take-the-ham-for-a-ride pricing when buying from specialist outlets.

Generic, China-made SDR dongle/box type.  Just £37!


Freeware is readily available for these dongle type receivers, and from all accounts, there should be very little I won't be able to hear for £37 that my mate paid £500 for his Elad.  In fact, according to one seemingly objective test, the Elad was trailing behind the cheap dongles on occasion!

Having played with the box of tricks for a day or so, I have to say the installation was absolutely infuriating!  This is because it needs a driver that, as I later found out, comes within the Zadig library with SDR Sharp, the software most commonly used with these units.  

A number of YouTube videos of this apparently exact-same box tell you to use sampling modes other than quadrature.  In fact, quadrature sampling was exactly what my box needs, and having selected this within SDR Sharp and then adjusted the bandwidth to 120000 on wideband FM (or just 10000 on AM), I suddenly found everything was working perfectly.

Apparently, a different driver is needed to access the HF bands, making this box much more cumbersome to use than initially meets the eye.  All the same, at VHF, I was amazed to find that, using just a simple dipole cut to the airband frequencies, I was picking up not only the aircraft but the regional controllers on the ground as well - in some cases a couple of hundred miles away, at least.  I never remember achieving that with any of my old scanners.


Wednesday 8 July 2015

Aloha DX!

Having long passed the phase of the hobby where competition either with others or myself is of any importance, interest in DX is now a much more enjoyable phenomenon of curiosity alone.



So it was nice to see, this morning, some fairly strong signals coming across to Wales from Hawaii on 15m.  At least two stations were active on the islands, although the one that called me didn't hear the my confirmation.  Having gained the WAS award already, I was still disappointed not to have the QSO made good!

I'll be on 15m a little bit earlier tomorrow, as this is an early hint of autumn-like propagation; plenty of long path JA was also coming in.


Saturday 4 July 2015

Programming Baofeng UV-5RC

I've recently been trying to manually progam the superb Baofeng UV-5RC in channel mode, which is not intuitive!  This came about because I have a new handheld satellite antenna that only has one feed, so channel programming is a necessity to cope with Doppler shifts and, sometimes, the need to use a different CTCSS tone to activate the satellite, as opposed to simply sending the correct access tone with each transmission.

The UV5-series handhelds sell for just £22, but provide great fun, with very good performance.
 
Coping with all these factors manually with two antennas and two transceivers is easy, especially if you have rotary knob tuning rather than 'up/down' buttons.  But it's absolutely impossible with just one transceiver doing all the work in the direct entry,  frequency mode.  So my new set-up forced a new way of doing things - programming.


There are some videos like this one out there, but I still found myself really scratching my head until I wrote everything down and went through it in a step-by-step manner.

Whilst a programming cable is very cheap, and can easily be made up from phono and USB cables, the following doesn't need any cable or the usual free software folks use - CHIRP - at all.

Here's how I programmed it for satellite operations:

Enter frequency mode (vfo/ORANGE BUTTON)
(Voice confirms mode)

Enter RX frequency e.g. 436.850

Press MENU

Enter 27 for channel storing

press MENU


Enter channel number


press MENU

voice confirms RECEIVING FRQ/CH

PRESS EXIT
--------------------------------------------

Enter TX frequency, e.g. 145.850

NEED ANY CTCSS TONE?  - if so, PRESS MENU > 13 > select required CTCSS tone

Press MENU

Enter 27 for channel storing (will already be on the earlier setting for RX)


press MENU
(voice confirms RECEIVING FRQ/CH)

Press EXIT.

DONE!

If you find the rig always returns a "transmitting frq/ch" voice no matter what you do, there's something already in that memory and you  need to delete its contents before you can fully reprogram it.  Enter MENU > 28 > MENU > delete the appropriate channel number, cofnirm by hitting MENU again.  You should now be able to enter the RX, followed by the TX frq as per the instructions above.





Friday 3 July 2015

Sandpiper Antennas 2m/70cm Yagi

Well, some years ago, I built my own stick-and-wire quads for 2m and 70cm, and to my absolute amazement, found it easy to work the SO-50 FM satellite with just a couple of Watts from a handheld.

Unfortunately, so far as I know, only SO-50 is available as an FM low earth orbit satellite at the moment, although any time now, AMSAT's FOX 1 is due to hurtle into space.

Weather - and my XYL's poor parking - took its toll on my 2m quad, and a 109mph wind that threw it up in the air in February 2014 meant its life was over.

Since then, I've been inactive on satellites.  So, not being minded to build another antenna for the time being, I opted to buy a Sandpiper dual-band Yagi. The current price is £88 including postage, which is not cheap, but not expensive, either.

The Sandpiper 2m/70cm Yagi.


The parcel duly arrived in a couple of days.  I did give advance notice to the seller that I'd be reviewing the antenna.

How does it fare?

Firstly, the impression of the packaging is a 6 out of 10.  The half cardboard tube, half crushed cardboard box wasn't very neat, and compared to the kind of proprietary tube in which the likes of Geoff Brown, aka G-Whip send their equally-priced mobile antennas out, it was pretty amateurish, to be honest.

I've seen better instructions.  More notes on matching would be useful...


The instruction sheet is a single sheet, with little by way of a step-by-step.  It's no problem at all for someone who's played with Yagis before, but it might be slightly daunting for a newcomer.  I thought the instructions could be a lot clearer with minimal effort.

The materials used are to Sandpiper's credit.  Just about everything is stainless steel, although grubscrews looked to be mild steel to me.  Not a big deal if you put a small amount of grease on them, or if you keep the modestly sized antenna indoors or in the car.  The 2m elements are very springy, which makes the antenna quiver a fair bit when held in the hand.  But that's just nit-picking; it's a perfectly sturdy, reasonably lightweight antenna that can clearly take anything the weather can throw at it in a permanent installation.

Stainless elements pass through demountable, wing-nut secured bolts.  Great for transporting.


I had hoped the antenna would be much lighter than I found it to be in practice.  Despite being marketed as "ideal [for] satellites", it has the usual problem of front-heaviness, so it quickly becomes tiring to hold.  A homebrew addition of a timber extension to the boom so that my forearm stops the thing from pulling down too much has sorted most of that out. As it is, you can just about manage a 10 minute pass without your arm giving up entirely.  In reality, there's little to suggest the practicality of hand holding this antenna for satellite work has been a consideration in its design.  With suitable changes, this could make the antenna much more attractive.

What (pleasantly) surprised me was the single feed.  The antenna comes with an SO-239 socket, which is not ideal at VHF/UHF, although the very short cable lengths used for handheld satellite work make this an academic issue.  The matching is achieved via a twin gamma match.  With both sets of elements in the same plane and interacting somewhat, adjusting for lowest SWR was not a trivial exercise; it took about 30 minutes for me to tweak everything, including some pretty significant bending of the gamma rods; the suggested setting length for 145MHz just wasn't possible out the box, as it was about 5cm too short!  Some sliding in and out of the elements might have helped here, which is mentioned rather unclearly in the instructions, and I'll try that out at some later point.

The single-feed, twin gamma match for 2m and 70cm, prior to fitting the shorting bars.  It works, but was very twitchy to match, especially on 2m.


Eventually, I managed to get both bands down to about 1:1.4, maybe 1:1.3.  That's acceptable for a twin band antenna and handheld at low power.  I'm pretty sure that, whilst it would make the antenna more difficult to pack in a car, it would nevertheless have better matching with elements at right angles.  The single gamma match probably mitigates against that design, though.

Here is the plot from my SARK-110 analyser for the 2m part of the antenna, performed several months after I first tuned it, and taking a more relaxed approach: it's best to match the 2m for lowest SWR, and not worry too much about less-than-perfect matching on the 70cm part, because that's only used for listening when satellite working.

Very good matching on 2m for the Sandpiper, but getting both bands matched is tricky.


For sure, tests on a 70cm repeater at 63km on the Isle of Man (line of sight sea path), showed the antenna to work very well, with a good front-to-back I'd estimate at about 20dB or more.  I didn't try the 2m beam.  Tests on SO-50 haven't yet yielded any results, as it was very late during a weekday, and the satellite passing extremely high to the north, with consequently no activity.

One thing I did find out through buying this antenna was the ability of the Baofeng UV-5RC to transmit on one band, and listen on another.  That's very handy, because otherwise, my single-feed Yagi would have been useless with one handheld tcvr!  This useful video helped greatly over reading some Chinglish manual that anyway doesn't seem to tell you how to do it!  It is much nicer, though, to listen to your own transmissions coming back, in which case the easiest and cheapest solution is two antennas (or two feeds) to two separate handhelds.  Without this feedback, and especially early on in the pass, you don't know if you're hitting the satellite, or whether it needs the lower CTCSS code to open the timer.  Those are bigger issues than you might expect. On the flip side, managing two handhelds or two separate antennas is very difficult, unless you have one antenna supported on a pole (which was my earlier arrangement.)

UPDATE:

I've now had a chance to test the antenna on a couple of SO-50 passes.  The signal on receive is very good indeed, and lacks nothing.   There's also no problem getting up into the satellite, as I managed several QSOs on a low-to-the-horizon pass just now.  The service, including packaging from Sandpiper gets a 6/10, dragged down by not-very-enthusiastic responses from the seller, and poor packaging quality.  The value for money gets a 7/10, and the quality of the antenna a 7/10, dragged down by the difficult matching and misleading claim that, once assembled, it can be disassembled solely by use of the wing nuts.  The instructions are 6/10.  Ease of matching isn't really something to score as such, but it isn't very easy, and bore little semblance to the suggested settings. A few minutes creating and posting an assembly and matching video online would probably help Sandpiper's customers and save them some time.

The antenna fits in the car quite easily, which makes it very useful for me, as I often find myself waiting for kids for hours on end, when a ham radio is very good company.

Would I buy it again?  I don't think the price is too bad, and having used it in anger on SO-50, can say I'm not at all disappointed by it - except for its pretty poor performance when the satellite is low in the sky; it's a very, very long way short of my old 5-ele up, 7 ele down quads in that respect. I'm not wildly excited by its matching and physical imbalance.  In fact, because of the need to adjust for Doppler shift and sometimes to transmit a timer-opening CTCSS tone that's different to the normal access tone, I was forced to get to grips with programming channels on my Baofeng UV-5RC.  Adjusting all the factors in Frequency Mode is impossible with a single handheld.  The single button press required to change channel and thus allow for the Doppler shift is, in fact, a much better arrangement than the earlier, direct-entry system I was using.

Whilst I was very annoyed at having to do so initially, now I have done it, it's actually much easier to skip up or down a few kHz with everything pre-programmed.  Just press an up or down button, and the correct shift is there on both uplink and downlink.  An additional channel stores the correct tone for opening the sat when it's gone into sleep mode!

So, it's fine if you want to save some time and get going quickly. It's also good for single handie use and ease of transport.  It's not so good for grabbing trans-Atlantic LEO QSOs, I'm afraid.   All the same, I'm hoping that, seeing a shiny antenna pointing skywards, folk outside the school or in the shopping car park will stop by, ask what the heck I'm doing, and leave amazed that a 'walkie talkie' is sending signals into space!