While I cannot understand why anyone would want to advertise the location of their car via a continuous beacon on a 2m fm radio, especially when the car is unattended in a car park, the devices offered by Byonics look interesting and may have other uses for the enterprising electronics or amateur radio experimenter.

The APO3 automatic power-off device is one example.  If your battery voltage drops below a predetermined level, it turns off the power to the radio.

Here is a link to the rules on the QRP club site.
http://www.vkqrpclub.org/qrp_hours_contest_2012.php

Summary:
1000 UTC to 1059: CW section 3500-3530 khz

1100 to 1200 UTC: SSB 3550-3590

QRP stations can work any station whether QRP or not.

Exchange is signal report plus serial number starting at 001. No repeat contacts.

QRP = output power no more than 10 watts.

Participation of higher power stations is appreciated as it warms up a contest to have more in it giving contacts.

I found the following US Navy website which has a universal calculator allowing you to find this data for your lat/long which can be extracted from your iphone or any GPS.

http://aa.usno.navy.mil/data/docs/mrst.php

For readers in the northern hemisphere, the calculator does allow for north and south latitudes, as well as west and east longitudes…

Well it is a big show.  Very big.  Have a look at the Hamvention website and you’ll find maps of the covered exhibition areas and the flea market area which is described as being 9 acres.  I observed that some lanes of what is normally a car park were not fully occupied, and some discussion on the hamvention mailing list (see yahoo groups) indicated that there were many more vendors in the flea market area in past years.

There were over 200 vendors in the covered areas.  The Dayton Amateur Radio Association (DARA) conducted exams for those who wanted to take out a ham licence, or upgrade from Technician or General to a higher grade. Candidates were lined up outside the examination areas all day, Friday and Saturday.  Hundreds must have been examined.

All the equipment manufacturers you have heard of and a lot you haven’t were present with impressive displays of their wares.

New to me were the Kenwood TS590 (HF/6m 100w transceiver), the Flex 1500 (HF/6m 5w transceiver) and the Elecraft 500w power amplifier.

I also saw a rotary 80m dipole on display from Array Solutions.  It looked to be about 50ft or 15m long, with loading coils and loading sections on each end of the dipole. It may have been shorter.

In the flea market there were many hundred vintage radios, ATUs, cables, antennas, connectors, you name it.  My vote for the most unusual item was the F16 simulator.

I came close to buying several new items but eventually just picked up some small components I want for my new antennas, some microwave attenuators and a G4DDK preamp kit for 2.4 GHz.

I met G4DDK at stand 915 where he and Kent WA5VJB were displaying and selling various items including a range of Kent’s pcb antennas including log periodic and skeleton horns for frequencies from 400 MHz to 10 GHz.

The event wound up officially at about 1pm on Sunday.  After that the exhibitor’s area was closed.

I missed out on a great deal I had been offered on an SDR-IQ receiver on Saturday afternoon.  I didn’t realise how many vendors would either close early on Sunday or not turn up at all.  I’ve emailed RF Space and have received a reply already, so all may not be lost.

Dayton Hamvention: well worth going and seeing it, but only if you already have a reason to go to the US.  It’s a long way for 2.5 days of hamfest.

At the VHF weak signal group dinner on Friday night, I met and chatted with a number of other people about VHF activities in Australia and heard discussions on contest rules that were familiar issues.  Should contest points be based on distance or on grid squares, or power, or what?  In the VHF sprints they are trying a distance based formula based on 6 character grid locators.  They have found that this approach has been well accepted by contest participants.  It is now quite feasible to calculate distances based on 6 character locators, since computers are so common.  Maybe this is what Australian VHF operators would like.  The grid square bonus system is much simpler but some people think it doesn’t give recognition or incentives for longer distance contacts.

Main arena display at Dayton

At Dayton Hamvention, May 2010

Main arena, Icom/MFJ end

At Dayton Hamvention, May 2010

Icom stand at Hamvention 2010

At Dayton Hamvention, May 2010 Read about amateur radio in Australia

Hustler antennas at Dayton Hamvention

Hustler antennas stand at Dayton Hamvention, May 2010 About amateur radio in Australia

Callbook booth at Dayton

At Dayton Hamvention, May 2010

IMG_5886

At Dayton Hamvention, May 2010

IMG_5889

At Dayton Hamvention, May 2010

Connectors and adaptors

At Dayton Hamvention, May 2010

Morse paddles for sale

At Dayton Hamvention, May 2010 About amateur radio in Australia

Keyer paddles for fast morse

At Dayton Hamvention, May 2010

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During the spring field day (28-29 Nov 09) we will also be attempting contacts with Doug VK4OE at Mt Kaputar near Narrabri.  The distance is about 500 km – to be confirmed.

We expect to work Doug on the lower bands (144, 432 and 1296 MHz) and will be trying for contacts on the 2400 and 3400 MHz bands as well.

Results will be reported here as well as in the WIA journal Amateur Radio.

One of these fellows was like the experts at the pub, who can advise you on anything from what is wrong with your car to what is wrong with your computer, TV, VCR and your dog.

His opinion was that multiband trapped antennas were nothing more than rotary RF chokes. His logic was that RF chokes have coils in them, so do traps, therefore a trap is an RF choke. His conversation partner agreed with him with a bit of a nervous laugh. This was a seemingly plausible argument but a bit worrying because most people use this type of antenna and they do seem to work.

The fact is that this is a silly conclusion to draw. Every radio has coils inside it to provide essential tuned circuits. That doesn’t mean they are RF chokes, preventing the transmitter signals from emerging on the antenna connector. How could it produce 100 watts at that point if the coils were choking all the RF?

However this kind of statement, if uttered with the right level of assurance and confidence, will feed silly ideas into the heads of less well informed listeners, asking them to suspend disbelief and accept such nonsense as fact.

A little thought about the traps in multiband antennas will reveal them to be specially selected sizes with a specific calculated inductance, to do their job and allow each element to exhibit multiple resonances. They are not RF chokes. RF chokes are coils with enough inductance that they present a very high impedance at the nominated operating frequency.  Perhaps our self styled expert thinks that is how traps work.  It isn’t.

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.