SOTA – 40m link Inverted V dipole antenna upgrade for 3.5 MHz

Get out of the Radio Shack and Live Life

In recent months 7 MHz NVIS propagation has taken a fall off the propagation-cliff to be replaced by its 5 MHz and 3.5 MHz siblings.

As the sun’s natural 11-year solar cycle moves closer to a solar minimum, radio amateurs are experiencing a change in the MUF.   Since January this year the NVIS frequency has moved south from a comfortable position above 7 MHz to 5 MHz and is likely to move lower in the next 12 to 24 months.  Unfortunately radio amateurs in Australia don’t have an allocation in the 60m band (5 MHz) therefore the next lowest frequency to attempt NVIS propagation is 3.5 MHz. Conveniently 3.5 MHz is available to all licence classes including the Foundation class.

For SOTA activators operating in the south-east of Australia and who get of bed early to be on a summit by 2200 to 2300 UTC (9 am local), now…

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SOTA – 4S 8.4 Ah LiFePO4 Battery

Get out of the Radio Shack and Live Life

A correspondent requested details of a lightweight high-capacity 13.2 volt battery, which I use to power my Yeasu FT-857D for SOTA activations. The battery is a 4 cell 8.4 Ah Lithium Iron Phosphate (4S 8.4 Ah LiFePO4) purchased from HobbyKing’s Australian (AU) warehouse in Moruya NSW.

Battery Dimensions: 150mm x 52mm x 70mm. Weight: 960 grams, round up to 1kg.

The battery is fitted with two 8 AWG leads terminated with 5.5 mm male (-ve) and female (+ve) bullet-connectors. The 5 pin JST-XH strip connector is for balanced charging. Rather than cut the bullet connectors off the leads, I decided to make a short DC cable adapter. One end of the adapter is fitted with a corresponding pair of 5.5 mm bullet-connectors, at the other end I installed a pair of 30 Amp Anderson Powerpole connectors. Why you ask?

In my shack I have standardised all DC power cable connectors…

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You Never know who your going to run into at a CHR coffee meeting

At our monthly Coastal Ham Radio coffee gathering we are sitting around discussing band conditions and the guy at the next table asks us if we’re hams?  We say yes and he says he’s a long time ham also.  We invite him to join us and he introduces himself.  Well a lot of years have past since we last saw each other and we didn’t recognize each other at first but it turned out, a bit after I got my license back in the ’80’s, he was one of the first hams I really got to know.  I can always remember one night getting a phone call from him saying we had to come over right away and see this.  My son VE7IKX and myself hopped in the car and got wowed at this new form of ham radio called packet.  At that point I was hooked on a digital mode albeit quite rudimentary by what’s going on in the digital world today.  Good to see you again Bob and hopefully you can join us again one day.