VK1DA's Blog

John Moyle Memorial Field day March 2009

For this year’s JMFD contest I thought weather and propagation conditions were fairly bleak.
The weather was wet and windy to say the least.  Many field stations reported having their tents and masts blown down.

The high point for me was working 3UHF on 1296 with only a single 18 el yagi, and barefoot (10w nominal).   The distance was 501 km according to the VK1OD distance calculator, using the VK1DA/p and VK3UHF locations from the VHF Logger.

I didn’t like my chances of having hf antennas stay up and didn’t want to extend the tear down process, so I limited myself to the vhf/uhf bands.  I had a car full of antennas and several extra masts but in those conditions, there is no point in trying to do too much.

The temp in the tent at 5AM Sunday morning was 3.5 C though the official overnight minimum according to BOM was 2C.   No wind gust peak data was available.

Operating techniques and problems observed.

There is a continuing tendency for operators to call and make contacts on only one frequency, 144.150.  Can everyone please tell their club operators that there is no repeater there, they are allowed to move the big knob in the middle of the radio panel.  It is ok, nothing will break, the rest of the band also works for making contacts.  It would be better to train vhf ssb operators on HF so they get to know how to operate on ssb, how to work the tuning knob and how to  tune around the band to find stations to work.  FM channels and repeaters are quite the wrong training ground for SSB but I’m afraid that the FM repeater operation mode (staying on one frequency, as if it is the only conduit to any other station) is the method many operators learn and continue to use.

It is up to the experienced operators to teach new operators better techniques.  I appreciated those experienced operators who I heard requesting a QSY as soon as initial contact had been made.

During the contest I tried many times to make contact with some stations in the greater Sydney and Melbourne areas, whose signals were perfectly readable, but whose operators seemed to want to chat to locals interminably, on 144.150.  There are bonus points for working longer distances and these operators were ignoring those chances.  eg. a contact with another local station is worth 2 points, but a contact with a station 300+ km away would be worth 50 points.  This surely would make it worth listening to a weaker signal.

We should encourage people to operate in vhf events in a manner similar to the HF bands.  Find a clear frequency (within the band plan) and call CQ.  If looking for a contact, tune the band.   If activity is low, don’t move too far from other activity (but be mindful of local interference problems – this is why I qsy 30 kHz up from 150, not just 5 kHz as I might on HF).  If activity is high, move further out.  Give the dx something to tune for.  Don’t clump up and make it impossible!

My QSO tally

All contacts ssb.  These scores are about half the corresponding number from the summer VHF/UHF field day in January.

6m – 9
2m – 54
70cm – 31
23cm – 7
13cm – nil.

Equipment sales: name your price

I have noticed some sellers of used radio equipment make life more difficult than necessary for themselves, by being quite unclear about what they really want for the gear.  ie. what is their asking price?

This is surprising because anyone who has bought equipment knows very well what they paid, knows what they got and usually has a good idea of whether they got a good deal.  You’d think anyone selling equipment would do a bit of basic research to find out what they are likely to get for a Bloggs XYZ120S transceiver.  But many people don’t do that.  You’d think their precious Bloggs transceiver was gold plated.  They should rethink what it is they are selling.

Radio equipment has a remarkably high resale value compared with most consumer electronics and certainly compared with motor cars we get huge prices for our old radio gear.  Why is that?  Before trying to answer that, let’s consider a few examples of unrealistic pricing or expectations.

One case is a Collins KWM2A transceiver with matching power supply.  These units were arguably the best you could get in their class for about 30 years, from the early 60s to the mid 80s and possibly longer.  They could barely be matched in even one respect by the best any other manufacturer produced.  The reasons – good design, simple operation, no frills, mechanically reliable and electrically hard to fault.  However this gear is now pretty old.  It uses tubes.  The manufacturer does not build these radios any more, parts are now harder to find and are becoming expensive.  Only the true fanatic will continue to maintain and use this type of equipment.  Modern equipment by other manufacturers offers much more in the way of operator conveniences apart from power and space efficiency.  So with this background we see a number of these radios being sold on the second hand market, sometimes with remarkably high pricing.  One ad even stated that since he had noticed similar equipment, together with a power amplifier being sold on Ebay for $US4000.  However he did not nominate an asking price and left it to the reader to work out what he would be prepared to accept. what should it be worth?  What alternatives are there that produce 100 watts on the bands from 80m thru 10m, with say 500 Hz dial readout and one VFO.  Well, almost none on the new market.  Even the cheapest Icom HF radio IC718 offers more facilities for around $800.  So to hope for any more than that is plainly based on the hope that there are people out there that want the equipment just for the pleasure of owning that particular brand or model.  Only the older operators will be at all interested in that thought, yet their numbers are diminishing.  So what chance does our seller have of receiving the $2500 he may think this is worth.  My feeling is, not much at all.

Another example is a portable multimode portable transceiver for the 420-450 MHz band.  This is a Yaesu FT790R.  3 watts output and modes SSB, CW and FM.  This is a curious gadget type radio, with insufficient power to make many contacts at all, unless you are located on the top of a tall hill or connected to a power amplifier.  OR it may be used as an intermediate frequency (IF) radio for higher bands such as microwave bands from say 2 to 10 GHz.  On those bands, using a higher IF is preferable to using 144 or lower frequencies as the IF.   So what is this type of radio worth?  Well, the latest version of the portable low power radio from Yaesu is the FT817.  It operates on all bands from 1.8 MHz to 450 MHz and produces 5 watts of any mode on all those bands.  It has digital readout and tons of memories, an inbuilt keyer and so on.  It is available new for just under $900 and is available on the second hand market for around $600 to $750 depending on age (5 years or 5 days).  So what kind of price should the seller hope to receive for his 20+ year old radio without warranty and spare parts availability.  Would you think $250 excessive?  So would I, but the seller in this example wanted $600 for his old FT790R (including a 10w power amplifier). In my view this is at least double its maximum value.

Another example was someone who should have known better.  A rare piece of Icom VHF/UHF equipment was advertised with a list of all the extras that had been loaded into it.   As my eyes ran over the listing, I searched for the asking price.  I found no clues given except for the amazing phrase “don’t make silly offers”.  Well, what is not silly?  How can a buyer read the seller’s mind and know what he has in mind for an unusual item like that?

In other consumer goods no-one would expect anything for a 20 year old transistor radio, or even a 2 year old MP3 player.  They get thrown on the scrap heap once the next model arrives.  Even more expensive goods like televisions and stereo gear is almost thrown out as worthless at the ripe age of 10 years.

In the case of used amateur radio equipment, you can be lucky and find equipment that has been looked after an used carefully.  The case is not damaged, the electronics inside it are all in good order.  No-one has made non-standard modifications (“improvements”) that reduce its quality of reception or transmission.  You can also be unlucky and find a radio is being sold because someone has discovered it does not work well at all.  With 20 to 30 year old equipment, the work needed to fix some problems can be quite expensive.   However there is currently a high demand for used equipment, which is artificially propping up prices for old equipment that should really be worth $50, not $300.

But what if you do think your Bloggs radio is a fabulous piece of equipment someone will love to use, and get heaps of service from?  Well, the least you can do is to look around first and see what they are selling for.  Be realistic, especially for 20 to 30 year old equipment.

But please, name an asking price and don’t expect buyers to read your mind.

Log spreadsheets available for download

Today I added some links and a page about some log spreadsheets I am giving to readers.
See Page links on the right for more details..

New antennas for 1296 MHz

I received the two 18 element yagis for 1296 Mhz and they appear to be strongly made. We will see whether they are any better than the previous antenna.  I have borrowed a splitter for them and will use that for the Summer field day in mid January, unless I can make my own before then.

I found a website offering data on stacking distances for yagis.  For a boom length of 1.5m on this frequency the stacking distance recommended is 2.4 wavelengths, which works out at 55cm (23cm wavelength).  The feedlines on the yagis are about 25 cm long but that’s not long enough to reach the power divider, so additional connectors and cable will be needed, eating into the stacking gain.

Next step for 23cm is to configure the power amplifier so it can be operated remotely from the tent.  I read some comments on the UK microwave reflector about power levels from IC910H not being up to the 10w level expected.  Time to get out the power meter and check mine out.

2.4 GHz transverter success

The 2.4 GHz transverter has been completed and I used it in the vhf/uhf field day on the weekend of 15/16 November.

Construction began on Sunday 9 November with the first components soldered onto the sequencer board, finishing on Friday 14th November when I finally measured the transmitter output power.

The next day I was on Mt Ginini, with a 24 db gridpack dish (obtained from The RF Shop) attached to the transverter, receiving a big signal from Ted VK1BL at Mt Coree.  I replied to his call and asked how he was hearing me.  He replied immediately! This was my first contact on 2.4 GHz, made all the sweeter by the knowledge that the transverter was home made.

Together with some other “firsts” on this field day, it made for a very good weekend.

I have written up the details of the design and construction and submitted it as an article for AR magazine.  The article was published in July 2009 and can be found in the AR archives here.

The 13cm transverter under test

Preparing for spring VHF/UHF field day, November 15/16

This week’s project is to prepare for next weekend’s VHF/UHF field day.

I plan to operate from a mountain southwest of Canberra, with equipment for 50, 144, 432, 1296, 2403 and 10368 MHz.  The first four bands are bands I have used before but the last two are new for my station.  The 2403 equipment will be a simple transverter driven by a FT290R radio on 144.  The antenna for that band will be a grid type dish.

The 10368 MHz equipment has been borrowed from another local amateur.  It is a transverter driven by an Icom IC202 on 144, the antenna is a dish.  It all mounts on a tripod which readily allows azimuth and elevation adjustements.

On all bands the main mode used will be voice, using upper sideband.  For some contacts with more distant stations, morse (CW) will be used as it is much easier to hear weak morse signals than weak voices.

Welcome to VK1DA’s weblog / blog.

Welcome to VK1DA’s blog.

I’m Andrew Davis.  VK1DA is my amateur radio callsign, which was allocated to me by the Australian Government once I satisfied the requirements for an amateur radio licence.

For more details of amateur radio licencing in Australia, please see my VKFAQ website.