June Shed Workshop – Tips and tricks for the iCOM IC7300

A number of members have the iCOM IC7300 transceiver as their primary base transceiver. One member has an iCOM IC705 which has a similar user interface.

This workshop provided an opportunity for members to share their tips and tricks in using the IC7300. Even those who didn’t own this rig, were able to learn more about iCOM’s user interface and its strengths and weaknesses. While the iCOM is straight forward to use, there are a number of traps that people discover as they go along. For example, if you have been using the rig on 10m FM (or similar) you may have adjusted the squelch control (which is shared with the RF volume control). When you switch back to 7.055 MHz for the Branch 50 NZART net on Sunday, you may find you can’t hear anything. Not even any band noise. You panic! What has gone wrong with my $2000 appliance? You may find the same result by turning both the RF Gain up full…. The answer is simple, always check the RF gain setting if you can’t hear anything. It needs to be set at about 11 o’clock if you want to hear something!

Presenters included Malcolm ZL2UDF, Frank ZL2TTS, John ZL2XJ, Bernard ZL2BD, and Mike ZL1AXG.

The presenters covered a range of topics including, pre-operating checks, simple controls (Gain controls, band switching, changing frequency on the waterfall display, using the attenuators and pre-amps, etc). They also delved a bit deeper into less frequently used features, including interfacing the rig to a computer, how to use the accessory outputs (e.g. to provide band-switching on a linear amplifier) and how to build a small interface to switch between pre-recorded voice messages for contest calling, and an explanation of various display modes (e.g. seeing RX and TX audio spectrum graphs on the display).

The shed meeting was held at John ZL2XJ’s QTH . A follow up session may be organised to cover things that we did not have time to cover – such as saving settings to the SD-card, software options for digital modes, and using the networking features of WFview software for remote operation.

Shed Workshop 4 July – High Current Switch Mode PS and Mixers in the Simple TXCVR

Our July shed workshop was held on 4 July 2021 from 1pm to 3pm at the QTH of Mike ZL1AXG (2 Derry Hill, Churton Park, Wellington).

Mike ZL1AXG is building Charlie Morris ZL2CTM’s Simple SSB Transceiver.  This is a modular design and as each module is completed it is tested.   In this second session Mike discussed design and construction features and demonstrated the testing of completed modules.  The module in the picture is one of two double balanced mixers constructed from scratch on veroboard (Photo from Charlie ZL2CTM)

Bernard ZL2BD also presented on high current Switched Mode Power Supplies suitable for driving Kilowatt amplifiers.  He designed a system using two SMPS at 24 v to power a 2Kw linear for another amateur.  The SMPS turned out to be very quiet electrically and they are available in 12v and 13.8v and other voltages as well ex China at very reasonable prices. 

Tea and coffee were available following the workshop.

Shed Workshop 13 June: An antenna ecosystem and Constructing a simple SSB Transceiver

Controlling field equipment under an ecosystem approach

The June Shed Workshop was held a week later than usual – from 1pm to 3pm on Sunday 13 June 2021 at Mike ZL1AXG’s QTH due to Queen’s Birthday weekend getting in the way.

Mike ZL1AXG and Bernard ZL2BD gave an introduction to the concept of an antenna ecosystem, in which a range of antennas could be controlled by a single microprocessor control system.  This includes remote antenna switches (with just one antenna cable into the shack), 4 square switching, directional switching of beverage antennas or similar, tuning of magnetic loop antennas, and rotator control for beam antennas.

Mike ZL1AXG also introduced Charlie Morris’ Simple Transceiver for 80m SSB. He showed off some of the modules that are under construction, and outlined in a block diagram the design of the transceiver. He demonstrated how the audio modules could be tested using a multi-meter, signal generator and oscilloscope by inputing a signal from the signal generator at 1KHz in the front end of an amplifier and measuring the voltage on the oscilloscope or multimeter at the output end.

Kordia equipment donated to QHUG

Kordia has kindly donated some surplus equipment for the QHUG future remote site. This includes two Datron 1Kw linear amplifiers and associated 28V power supplies as indicated in the images below.  These will be straight forward to connect up to amateur transceivers at the remote site.  We were also gifted two Datron transceivers that could be used for a range of purposes (e.g. beacon stations or for fixed frequency digital mode use) and a Furuno receiver.    These donations are huge boost to the project!

Linear amp photo #1Linear Amp Photo #2