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December 2000

Beechlog
 
The on-line magazine of the Burnham Beeches Radio Club.

World Wide Web Edition December 2000
Hello and may I wish you a very happy Christmas.

It seems only a few days ago that I was trying to compose the last issue of 1999, but here we are a year later. There have been quite a lot of changes in the UK amateur radio scene since last year. The A/B licence is now firmly established (except in BBRC - come on Paul), and I now hear Novices on 2 metres. The world hasn't ended as a result of this, contrary to predictions by some die-hards, and Morse is still fit and well on the bands.

More changes are on the way, and personally I welcome these. We cannot turn the clock back to some 'Utopia' where amateurs were real men, but we can ensure that there is plenty of opportunuity for newcomers to join us and blow the cobwebs out of our dusty minds.

Roger G0HZK, Editor
Contents

Marks Wedding, Proof of the event, but where's the bride?.
The Ditter, How the ARRL tracked down a mystery on 14MHz.
Small Radios, a few thoughts about my radio shelf!.
Being in hospital, hoping I don't need a pacemaker.

Yes, it's finally happened!! This is what working in the USA leads to!!









What are these strange things around their necks?
Many thanks to Mark for sending these pictures.
ARRL VOLUNTEERS FIND, FIX "THE DITTER"

I recently joined the ARRL, mainly for the very good publications they issue. See info at the end of the story. Paul G6TSF

This is a true story, I hope this or any thing like it never happens to you. It is brought to you from the ARRL Newsletter (ARRL is the American Radio Relay League and the FCC the Frederal Communications Commission) thanks to Brennan Price N4QX.
ARRL staffers were greeted the morning of July 24 with reports of a continuous string of CW dits near 14.008 MHz--heard throughout North America over the preceding weekend. Initial reports gave conflicting beam headings of the offending signal, dubbed "the ditter." But when FCC staffer John Reiser, WQ4L, called ARRL to report his observations, things started to happen.

Reiser facilitated an FCC DF trace to the San Diego area. The ARRL San Diego Section leadership was notified, and Section Manager Tuck Miller, NZ6T, coordinated local hams in a close-range DF effort. San Diego section Official Observer Coordinator Bill Sallee, K6TWO, took several field readings. At one point, when he'd narrowed the location to within two miles, the signal abruptly disappeared. The ARRL Monitoring System also was alerted. It was confirmed that this was a normal CW signal, not a "woodpecker"-type intruder.

Dialing around the bottom edge of 20 meters early on July 26, IARU Region 2 Monitoring System Coordinator Martin Potter, VE3OAT, heard the ditter once again, this time near 14.026 MHz. Potter determined that the signal had an identical period and beam heading as the one heard earlier. He notified ARRL Headquarters, and the San Diego hams picked up where they'd left off.

Sallee's field strength readings drew him closer and closer to the coast, where the heading reversed. Sallee reports that he ultimately found the apparent source in the oceanfront community of La Jolla. He says the woman who answered the door said her husband was a ham and allowed Sallee to take a look at the station. Sure enough, a stuck dit paddle was keying a powered, unattended rig, which Sallee disabled.

Sallee theorizes that heating and cooling within the ham's uninsulated shack and a combination of corrosion in the keyer paddle's pivot mechanism and close dit contact spacing contributed to the contact's migrating to a closed position. He said the ham later told him that he'd been operating on 14.007.5 MHz on July 21 but did not return to the shack until Monday afternoon. "He remembers listening to a CW contact on 14.026 but did not transmit," Sallee said. "He then left the shack unaware that by leaving the rig on, he would fall victim to unattended transmission when the moisture and temperatures began to change."

Sallee says the ham, whom he did not identify, "was most embarrassed."

"I really felt sorry for him and assured him that public hangings were no longer in vogue," Sallee said. "He said he had learned a valuable lesson about disabling a rig that will be unattended."

Potter congratulated the ARRL Monitoring System and the San Diego field organization for what he called "a fine example of quick reaction and good, solid work" on tracking down the unintentional transmission.

Brennan Price, N4QX

Small Radios

I have a small computer desk in the kitchen. This was fine until I got a computer and all the paraphenalia that goes with it. You have no idea how big a monitor is, or how much space a few CD's take, and where does the printer go? Then there are all the other bits, numerous moulded black power supplies, scanners, etc. that need a home.

I have two small shelves above the desk. They are almost 11 inches deep, and about 18 inches wide. These are my radio shelves. On there sits my TR751 two metre SSB radio, and its 'linear' amplifier. A thirty amp power supply, and my ICOM 725 HF radio. My SWR meter, ATU, handhelds, transverters, converted CB, books, and my collection of audio CD's.

The HF radio fits nicely, but, it fits only if there is nothing connected to the aerial lead, and nothing on the power supply socket. My Morse key can't be plugged in, which is why I don't use CW :-)

This December I decided to do something about it. I couldn't make the shelves deeper (the cupboard door needs to open) or wider (back door in the way), so the only answer was a smaller radio. I considered building one, but since developing an allergy to solder flux, I decided it was time to lash out.

There are four small radio available, so I went to look at them in Martins shop. They are Yaesu FT100, Icom 706IIG, Alinco DX70TH and Kenwood TS50.
I thought it would be nice to include a new band or more in my purchase, so the Kenwood was out, being 1.8 to 30 only. All the others have 50 megs, and the Yaesu and Icom have two and seventy cems as well.

The Alinco is a nice radio. It is probably the easiest to operate, and the best RF performer. But it is also the biggest, where it counts, in depth. Alas it was not much smaller than my Icom 725, and even with a right angled plug on the aerial, it was going to be a tight fit. This would also prove a problem in the car. (Martin had an FT90 FM mobile in the shop, my goodness this radio is small!)

So the 706 and the FT100. These would also allow me to operate on two metres in the car, and even 70 cm SSB. I liked the latter, I once had an FT780, and worked further on this than on 2 metres for a while. These two radios are very similar in the facilities they offer. The 706 has been around for about 3 years or more, and by now the bugs should be sorted out.
In fact the main annoying feature was the lack of drive from the microphone on SSB, and the latest model is still the same. There was a bit in RadCom (and on the net) about how to improve it, including twiddling pots inside, although this is reputed to be less effective on the IIG model than earlier versions.

The 706 works quite well, I have one on loan from Martin at the time of writing. There are a few things I have noticed, like Radio 4 on 93.5MHz distorts a bit, I think maybe it is a little overloaded. There are a few other things too, like you cannot set the power to different levels on different HF bands, nor can you set FM tuning steps differently on the FM bands. This latter point is an annoyance. 10 and 6 metres need 10kHz steps, 2 metres 12.5kHz, and 70cms needs 25kHz. A simple bit of maths (lowest common denominator) shows that 2.5kHz is needed, but this is not available. The nearest available setting is 100Hz, which is a joke on 70cms. This setting is not saved in memories either.

However the answer is to use the memories for the FM channels, i.e. one memory per channel, although this will use up most of the memories.

The 706 can be programmed with different repeater shifts for each of the four FM bands, although the shift direction needs to be manually set by pressing the duplex button once or twice. There is an auto repeater mode, but this is for the US only (this is an EU model). Once again memories are best used for FM.

For SSB the 706 works very well. The tuning knob is super, and you can tune in 1Hz, 10Hz, or 1KHz steps. The auto-notch filter is magic, and the meter can be easily cycled between Power out, ALC, and SWR. The audio speech compressor helps increase the average power, although not a patch on an RF one. Split frequency operation is easy once you have sussed it. The RF gain is a strange knob, full gain is at 11 O'clock!

Finding your way around the menus is a bit messy, although easily learned. Changing settings like power, ctcss tone, tuning step, is quite easy, but to change many other settings you need to turn off the radio, and switch on again holding in a button.

The manual is quite detailed, and shows drawings of what is hiding under the covers. There is no circuit diagram, but the pinouts of the main external connections is clearly shown.

The 706 sits quite well on my shelf, even though the aerial sockets are mounted on the back panel. There is a large lump on the power lead - a filter required for EU approvals. This lump make mobile mounting a bit more difficult, although my Icom 725 has the same lead with no lump, I could swap them round.

The FT100 is a few millimetres deeper, but the power and aerial connections are on flying leads. This means it fits very well on my shelf and in the car (mobile bracket included). I can easily swap HF and 6 metre leads without moving the radio. This radio also has a lump on the power lead, this time a sort of fuse-box, but it is more easily tucked away.

All the FM problems on the 706 are sorted in the FT100. You can set individual power levels and tuning steps for each mode of each band. Repeater offsets are automatic and largely suit the UK bandplans. Deviation can be set to 2.5 or 5kHz.

The settings are less confusing than the 706, and you don't need to turn off the radio at any time. The display has more graphics, showing various useful icons. The notch and noise reduction filters are similar in effect to the 706, and there is an additional band-pass audio filter, which you can set the LF and HF boundaries independently on SSB. You can also use it to vary the audio width on CW.

The FT100 tuning knob is not so nice, and a bit small compared with the 706. Since the radio is about the size of my two metre multimode it has to be small. On FM, the main tuning know is locked (it can easily be unlocked by the press of the lock button), tuning is carried out with the multi-function step switch, which is set correctly for all FM and WFM bands, and makes it easier to change frequency when mobile. This same switch also works on the other modes, making quick QSY's easy.

Being a smaller radio, the display is smaller too. This means that some of the indicators are missing, although by cycling through the menu you can see what settings are selected (the legends, e.g. SPL, are bold). This is not ideal, but then the 706 is a bit inconsistent too, with indicators all over the screen, and red and green lights whose meaning is uncertain.

The FT100 tunes from LF to over 900 megs. Airband AM was very nice, and broadcast FM quite good too. There is some breakthough on some frequency bands, but not in the ham bands. I heard some Americans on six metres, but only the kilowatt merchants seemed to be working them. I had many QSO's on two metres, including the Isle of Man - reception and transmit audio were fine. The FT100's S meter is a bit stingy. The Amersham 6 metre repeater was about S9, while on the 706 it is S9+60dB, but still a bit of hiss on the signal. It is possible to increase the meter reading.

On Saturday I had an FT100 here, but there was nothing on the display! I took it back to Martins, where they immediately replaced it. After the shop closed, I discovered that it was oscillating out of band on 10 metres! They checked all the radios in the shop, they did it too! Then yesterday Yaesu UK checked all theirs - guess what! Yaesu UK contacted Yaesu Japan - they knew about the problem, and had shipped spare boards to the UK. They promise to deliver tested, working models tomorrow, so we'll see.

Roger G0HZK

Being in hospital

I read somewhere that as you get older, you generally find you have some medical condition for every 10 years of your life. So for me in my early fifties, there should be five things wrong with me.

Apart from the usual personality defects that my wife will tell you about, some of you may know that for the last two to three years I have suffered from a form of tachycardia. This is not uncommon, and in my case has meant that two or three times a year my heart suddenly takes off at 150bpm or more, quite uncomfortable when you are used to a steady 65bpm or so. This varies with different people, one workmate gets this business going on for about 1 to 2 hours. Of course I don't do things by halves, and it usually lasts around 15 hours, long enough for me to decide to admit myself to Wexham Park Hospital. The service I get there is generally excellent, it seems that this condition means I don't have to wait long in A&E.

After about three visits, they decided on some drug treatment. One of the other conditions I suffer from is Asthma, which drastically reduces the type of drugs I can take, and means I can't take the most effective ones. So Wexham referred me to a consultant in London, who could carry out "procedures" to attempt to correct the problem.

So after about 5 months I got to see this chap, who recommended an "EPS" and possible "RFA". Now I have never been anything other than an outpatient in any hospital. My wife, who has spent many sessions in operating theatres, and who recently got herself a job in them, is unphased by all this. I am a compulsive coward.

I was then informed that there was a 12 month waiting list, but I would be treated earlier if my had any health insurance. Thanks to belonging to the same scheme in my last and current employment, this turned out to be possible, so here I am in the Royal Brompton Hospitals private ward.

The advantage of this treatment is that I can come off the drugs, well hopefully. I have also been avoiding foods that are suspected of triggering these episodes, like alcohol, tea, coffee, many soft drinks, but excluding water which thankfully I enjoy drinking. I also avoid any food with monosodium glutamate, which is just about anything with a brand name, or anything Chinese. This infuriates my wife, who thinks I do it deliberately to make her cooking difficult. Two of my children are faddy, and two vegetarian, and me, means we rarely all eat the same thing.

Coming here as a private patient is, I guess, not the same as National Health. For a start, my room has a wardrobe, chairs, a telephone, a TV with subscription channels, a fridge, and a fully equipped bathroom. The meal - well the breakfast menu fills an A4 sheet, lunch and dinner much the same. The ward is also licensed for beers, wines and spirits. There are pictures on the walls, and a fine view across London.

Within minutes of being given this room, I am met by my nurse, a (for want of a better term) waiter, and a doctor. I get fully examined and asked a long list of questions, and get told about all the various services available. A couple of hours later the consultant arrives, who tells me exactly what he is going to do, and discusses various types of pacemakers that I might benefit from.

This "procedure" consists of inserting wires into my heart, fed in via tubes insrted into my groins. I learn that I will be fully awake during all this. Hmm. So a few minutes later I am wheeled down to his "lab". The squeamish should perhaps not read any further, I certainly have avoided any medical books and don't watch Casualty.

In the lab I lie on an X-ray table, which seems about 10 inches wide. The lab is filled with all sorts of machinery, and has a sort of control room along the side, rather like a recording studio. I get wired up to some sort of ECG machine. There is an array of huge monitors, on of which shows my name on the screen, others show ECG traces and X-ray images.

My wife, who worked in operating theatres, had told me tales of what goes on. There is the background music, and the light-hearted banter between the staff. She is right. During the "procedure", the consultant warns a female doctor about the seductive powers of the male doctor she is going to lunch with.

The actual "procedure" is "interesting". The bit where the tubes are inserted in my groins wasn't exactly entertaining, but at least there was a local anaesthetic used to numb them during this process. I could see the path of the wires on the X-ray monitors, but thankfully wasn't aware of any sensation as they were fed through.

When the wires were in position, they sent impulses into my heart which stimulated the tachycardia. The next step was to take measurements to find out where the unwanted conductive paths were. There are a number of possibilities, including the prescence of extra pacemakers in the right atrium or right ventrical. In my case they found paths close to the A/V node (which is a sort of junction box for the signals from the pacemaker in the right atrium).

So having found these, the RFA (Radio-Frequency Ablation) procedure began. Firstly they set my heart to the normal speed. Thankfully again I wasn't aware of any sensation as RF was used to burn away these paths. This happened many times - the consultant assured me that I wouldn't need an electronic pacemaker.

They then tried to stimulate the tachycardia again. This didn't work, so they tried various drugs. One of these just made my chest pound rather uncomfortably. Another was most unpleasant. Described as a stress hormone, this sent a wave of undescribable nastiness up through my body. I think it was rather similar to the feelings you would get when placed in a frightening situation (as if I wasn't) such as being chased by a pride of lions. The doctor said it would only be brief, which it was, and a couple a minutes later I felt "OK" again.

Apart from this stress hormone, nothing really unpleasant was felt. It was rather strange when the doctors took control of my heartbeat. I guess my body normally knows when the heartbeats are, so they were occurring at times unexpected by the rest of my body. After about ninety minutes of this, the consultant decided that nothing else would be accomplished, so after a couple of final "burns" they pulled out the wires and sealed me up again.

So, back to my room. I have to lie still for about four hours, without moving my legs. This was not exactly comfortable, but I was offered food straight away, and the hotel service begun. Every half hour the nurse came in to take various readings, and I was wired up to a mini ECG machine which somehow transmitted its measurements to a monitor at the nurses desk.

So I am writing this the following morning. I've just eaten dinner, and am waiting for my wife to turn up to escort me home. I now have to see what happens. I am off the drugs, hopefully for good, although there are still probably a few things wrong with me that I haven't yet noticed!

Roger G0HZK