|Antenna HF: ||20m half-wave dipole, approx 5m above ground (see MW0LLO HF Antenna. (links to http://www.mw0llo.com/hfantenna.aspx))|
|Antenna 2m/70cm: ||Diamond X-30 (from Mark, 2W0MBK)|
A close-up of the base of the Diamond X-30, showing the three radials.
The Diamond X-30 installed on an aluminium mast supported by 18" T and K brackets.
|HF Feeder: ||ladder line from dipole centre to just outside shack, connected to RG58 coaxial balun. RG58 passes through wall of shack and connects to AMU.|
|2m/70cm Feeder: ||RG213 from base of antenna through to shack. Not flexible enough to connect directly to small transceiver (IC-E92D), so instead terminated in 'N' connector and then to 'N' coupler. The coupler can be connected to one of a number of smaller RG58 cables. One of these is terminated in an SMA for the IC-E92D, another is terminated in a PL259 for connection to the IC-275E.|
The 'shack' is a small first floor room at the back of my end-terrace house.
Antenna Matching Unit.
- MFJ travel tuner (bought for use with MKARS80, but currently being used with FT-950)
VSWR \ Power Meter.
(links to http://www.mw0llo.com/images/vswr.jpg) SWR \ Power meter, rated for 100W.
- Watson Power Max 65 NF 60 Amp power supply
- Maplin XM20W PSU (for use with MKARS80)
Transceivers and Accesories.
|Base HF\6m Rig: ||Yaesu FT-950|
|Base 2m Rig: ||Icom IC-275E (from Dave GW4HBK)|
|Base 2m Mic: ||Icom HM-12|
|Handheld 2m/70cm: ||Icom IC-E92D|
|Handheld 2m/70cm 2: ||Yaesu FT-51R (and CA-9 base charging stand, NC-55C Ni-Cd battery charger)|
- Home-built MKARS80 80m LSB transceiver
- MFJ Cub (20m). Must learn Morse Code !
- Home-built rig-to-pc interface (from Feb 2009 PW article, for use with MKARS80).
- Dell Latitude D620 laptop running Windows XP with various bits and pieces of amateur radio software
- Yupiteru MVT-7100 Scanner
- miniVNA from mini Radio Solutions
- Wien-Bridge based Audio Oscillator. (links to http://www.mw0llo.com/audiooscillator.aspx)
- Gould 20MHz Oscilloscope.
- Old Maplin "Precision Gold" DVM.
- Digimess Frequency Counter.
- Dip Oscillator.
- Noise Bridge.
- Marconi Instruments 2018 Signal Generator 80 kHz - 520 MHz
- Rigol DS1052E Oscilloscope
- Tektronix 475 Oscilloscope
- Gw Instek GFG-8216A Function Generator
Marconi Instruments TF2370 110 MHz Spectrum Analyser
This was purchased from a fellow member of Cwmbran & District Amateur Radio Society (links to http://www.mc0yad.co.uk/), John GW0OAJ. It includes a tracking generator. These are a few of the key features:
- Frequency Range: 30Hz - 110MHz
- Input Socket: BNC
- Input Impedance: 50Ω
- Maximum Input: +25 dBm continuous (4 V r.m.s.), +30 dBm for five minutes (7.1 V r.m.s.).
Comments on Existing Equipment.
The Watson PSU is a bit large really, but was purchased for a bit of future-proofing (and because I got a good deal when thrown in with the FT-950). It has an annoying habit of switching on its very noisy cooling fan when even a small current is drawn on receive. Perhaps when the PSU is a bit older I will modify it to correct this or install a quieter fan. The PSU has a rotary control that allows the user to change the frequency at which its internal switch-mode circuits work - this helps to reduce QRM especially on the lower bands (80m and 160m). In practice, I found this adjustment to be an annoyance (it is enough work to operate the rig without having to also operate the PSU!). So for now, I have resorted to a car battery as a PSU. This is recharged via a solar-panel during the daytime whilst I'm at work. I can keep a check on the voltage of the car battery from the FT-950 which has a voltmeter feature.
A longer-term solution might be to locate the PSU further from the rig and to homebrew some substantial filtering to reduce its QRM to more manageable levels.
The MFJ Antenna Matching Unit works surprisingly well for such a small piece of equipment. As I current only have a 20m dipole antenna, the FT-950's internal AMU will sometimes struggle to get an acceptable VSWR for the band I am using. The travel tuner is then used for these higher VSWRs. The controls on the front of the AMU are a little too small (it is intended for travel after all), and so repeatability of the settings is tricky.
As the antenna is a balanced arrangement, I am currently operating with no RF earth. Also, I don't have any kind of lightning protection (it is unlikely that my antenna systems would receive a direct strike, but I know that equipment can be damaged by voltage transients from nearby strikes). The next step must be to improve the safety of the station and provide these features.
The AMU should be upgraded, so that it is easier to operate and can handle the UK license power limits.
Better filtering of the mains power supply would be nice to reduce QRM.