Author Archive
160m/80m DC transceiver
These are bands I rarely use, but some readers may be interested in the Hendricks Kits dual band transceiver. 5.5W sounds enough to work plenty.
These days, the main issue on these bands can be man-made noise from TVs, SMPUs and similar. At my old QTH I had an S7-8 noise floor on 160m and 80m. At the new QTH the noise floor on these bands is low currently, but this could change overnight. Some people use loops and nullers on RX to minimise problems. If you have a quiet noise environment then this transceiver may fit your needs. Don’t forget you will need a reasonably big antenna to get decent results. A half wave 160m dipole antenna is around 240 feet long.
In my youth we had rigs like the Codar AT5 12W AM/CW 160m/80m transmitter and companion T28 RX. I had the RX but not the TX although I did use an AT5 from the QTH of the late G4PJ. The T28 was mainly used as a tunable IF for my 2m converter. I heard my first 2m satellite signals via Oscar 6 and 7 using the T28 as a tunable IF. I remember being very thrilled hearing my first transatlantic stations on the top end of 2m.
The Minima transceiver
See http://www.phonestack.com/farhan/minima.html
This is the latest project from Ashaar Farhan. Component cost is said to be less than $100. This is based around a Si570 sythesiser and a programmed Arduino micro-controller IC. It looks a simple to duplicate rig covering up to 30MHz. It is the successor to the BITX rig I think. The IF is 20MHz. If you only want 0-15MHz or 15-30MHz (i.e. not both) the rig get even simpler.
As it stands it produces 1W pep but it is easy to add a further PA.
Although a kit of parts is available, I am not aware of a full kit with enclosure and a PCB being available as is the case with the BitX from Hendricks Kits.
Crystal alternative?
Buying crystals for specific frequencies is now getting very expensive. There may be a newer alternative.
See https://aa7ee.wordpress.com/2015/01/12/a-crowdfunded-si5351-breakout-board-from-jason-nt7s/ .
This synthesised solution allows any frequency from 8kHz to 160MHz to be generated.
GQRP Club
Many times before I have said that SPRAT is the last magazine I would give up if I had to. GQRP Club membership is very reasonable indeed and I highly commend it to you. They now sell a DVD which has the first 160 copies of SPRAT on it. If you join the club, the DVD is very inexpensive plus you get the next 4 SPRATs with the subscription. SPRAT is always filled with good stuff and always plenty of projects to build.
Go on, join!
6m – magic band, really?
Why do I bother on 6m WSPR? Apart from G6AVK (78km) with whom I exchanged spots more than a week ago I have had no success at all on 6m WSPR out of the Es season. I get plenty of success on 10m with less power. I go on 6m WSPR because I can do so at the same time as being on 10m. I get far more success on 630m with an ERP of just 5mW. I think I am going to give up on the “magic band” until April or May. Maybe I really do need 100W and a big yagi up high in the sky to make the band “magic” at this time of the year. My 1W ERP from a V2000 vertical omni antenna just isn’t enough or maybe all the activity is on other modes?
My shack
Shack – operating position Jan 8th 2015 |
As many of you know, I had a cerebellum brain bleed in Sept 2013 which was operated on. I am steadily recovering, but my voice is still poor so I much restrict operations using voice modes for now. The picture shows the operating position in my shack. As shown, I am using 500mW on 10m WSPR (WSPR-AXE-CW beacon) and 5mW ERP on MF WSPR via a homebrew transverter (just below the clock) and the earth-electrodes in the garden. MF uses the PC and FT817 whereas the 10m beacon is tiny and needs no PC. The loading coil (above the power meter) is not used with the earth-electrodes. It is used when on MF when loading up miscellaneous other antennas. It is not in use at all currently.
When fit again, I intend to resume field experiments.
Not shown are any of the optical, 136kHz or VLF kit or the bench used for building. The latter is currently awaiting better health again.
Early days on 2m
My first ever RX outings on 2m were with a derivative of the CQ2 super-regen RX circuit from Practical Wireless back in the late 1960s. The very first signal I ever heard on 2m was G3VEH/P on Caradon Hill in Cornwall. I was located at Kingsbridge in South Devon. I used a small crystal earpiece and a 19 inch whip. The same receiver was later adapted with the addition of an RF amplifier in my Fredbox AM transceiver. These were the days when AM was still king on 2m. The best DX contacts with the 10mW Fredbox were impressive.
A few years ago, I rebuilt my Fredbox and had a few local QSOs on 2m AM. It still works well for something this small and simple. More details of the Fredbox are on my website. Follow the link above.