I thought I would share a few comments about my new radio, a Ten Tec Rebel, Model 506. I have owned this radio for about three weeks, but for two of those weeks I have been out of action (illness). However, I have listened to some CW transmissions on 40 metres and I intend to keep the radio on that band. It is capable of transmitting on both 40 metres and 20 metres, CW only at about five watts at 13.8 volts, a little less using a 12 volt supply. The radio is an open source Arduino based device for tinkerers! But is it ready to transmit on either 40m or 20m depending on the band you select by changing five sets of jumpers. There is no frequency readout but the default 40 metre frequency is 7.030. Changing frequency is achieved by setting the frequency step, turning the dial and counting the led flashes. I listened to some SOTA activations on 7.032. I already own a Ten Tec Argonaut Model 539 and the controls are very similar to the controls on the Rebel. There is a Rebel Group on Yahoo and many US operators have added additional features to their Rebels, for example, frequency readouts, band changing circuitry, additional bands and a morse keyer to name just a few. I have armed myself with the ARRL publication ‘Ham Radio for Arduino and Picaxe’ edited by Leigh L Klotz, WA5ZNU. I would rank a frequency readout as a useful add-on. Anyway it is my intention to use the radio on portable operations and try my hand at some slow morse contacts.
The radio is packed in a cardboard box after being shrink-wrapped to a piece of cardboard which is fitted to the bottom of the box. There is no foam. Indeed no additional packing at all is used. I was impressed. The radio is very small and no accessories are included in the package. You therefore need to add a speaker and make up a power cable, connect to the power source and attach a hand key and it is ready to work. The radio is very small: about the size of two cigarette packs side by side! For anyone seeking more information I thoroughly recommend the You Tube videos from NG9D. I will say more about this radio as I get to use it more.
In recent times I have renewed my interest in portable operation specifically using QRP radios. My equipment is an FT817 and a Ten-Tec Argonaut VI. My antenna is a home made linked dipole for 20 and 40 metres together with a light weight SOTA linked dipole from England.
My linked dipole is rugged and great for parks use and probably alright for a summit as well. I use Mark’s (Tet-Emtron) dipole centres and the Kevlar centred wire. This wire is very strong and light and does not kink. Its construction is similar to coax. There is an outer plastic insulating cover, a mesh conductor (braid) like the shield in coax and the centre contains the Kevlar. My approach to soldering this wire is based on a few experiments. Where the wire goes inside the Power Pole lugs I stripped the outer insulating material off to the correct length, then pushed the braid back and very carefully, using side cutters, trimmed three millimetres of Kevlar off allowing me to then twist the braid into a point or spade shape. I lightly tinned this and then placed the Power Pole lug over the wire and applied a hot iron to that point on the lug where the cylinder containing the wire gives way to the spade. The solder flows through the cracks. I then run the iron down the join on the cylinder to complete the assembly. You will notice that the soldered joints are not load bearing. To erect the antenna slide the dipole centre hole over the squid pole ensuring that the SO239 is facing down. Attach the coax before pushing up the squid pole.
I have two ways of mounting a squid pole. The first is to use a PVC plastic sleeve slightly larger than the base of the squid pole and lash the sleeve to a post, rock, fixed picnic table or something similar. The sleeve protects the base the squid pole from being crushed. The second method is to mount the squid pole on a tripod (in my case a speaker tripod from Jaycar). You can see this approach in some of the pictures. I have made a bracket that fits over the top of the tripod and this contains two baluns for antenna experiments. On occasions with light winds I do not need to guy the tripod or squid pole, but if the winds are reasonably strong I guy the whole assembly. You can see this in the picture of the Cooltong CP activation.
Well you might ask, what’s the difference between an FT817 and a Ten-Tec Argonaut VI as far as portable QRP operation is concerned? The major differences between the two transceivers are as follows: the receiver in the Argonaut is better and less prone to suffer from strong signals near by (5 KHz or less) and second, the Argonaut has a splendid variable width SSB filter, which is really effective. There are many other differences, but the ones that count are the Argonaut has a speech processor, the current drain is less for receive, the display is larger and visible in bright light (using the default colour of blue) and the DSP is excellent. However, it is a little larger than the FT817 and, while it is rugged, it is not as suitable as the Yaesu as a back pack radio. I have fitted the 2.4 KHz SSB filter to my FT817 and it does improve receiver performance. I like both radios and will admit my comments are entirely subjective!