My Shack
name02

LAST UPDATED: 21st March 2015

Welcome to my shack! This is the room (or rather part of a room) where all the radio gear is located. I have arranged my equipment so that it is easy to use and everything I need to adjust is within reach. Having an efficient layout is very important, there is nothing worse than having to stand up, stretch or reach over to adjust a control, especially when you are in the middle of a contest or chasing that elusive DXCC. My equipment is stacked vertically (as opposed to the more common side-by-side arrangements usually seen), which allows me to arrange my equipment in a very small space whilst retaining usability. The image below detail the various important components of my radio gear. The main radio is an Icom IC-756pro (the original ‘pro’ version) which covers HF and 6m. I have used Icom gear for a good many years now and rate it very highly. To get the most out of my equipment, I use some ancillary equipment such as a Comet CAT10 ATU to match the antennas to somewhere near 50 Ohms. The Datong FL2 is an analogue (not DSP) audio filter that is well respected all over the world. The FL2 gives a real boost to weak signals and pulls them out of the noise. Good headphones are a necessity and for HF work, the Kenwood HS-5’s (see image below) must rate amongst the best. The are not cheap, but boy do they work! They are no good for hi-fi listening as the frequency response has been tailored specifically for communications. The MFJ1026 phaser is used in conjunction with the main antenna (now just a parallel dipole in the attic) and the active loop. I also use The excellent SDR-IQ from RFSpace. This is a great, USB bus powered receiver covering up to 30MHz. I also have  another SDR receiver, this time it is the superb FunCube Dongle (FCD) Pro+. A flash drive sized dongle that covers from 150kHz up to around 2.1GHz, with low noise and good filtering. Listening on 4m and 2m ssb is a revelation. I recently did comparative tests with the Netsky SDR dongle, the results are on my 6m/VHF FM page.  I run the IC756pro on my 6m dipole and, with the help of the MFJ preselector, this does a great job on both 6m and the upper HF bands.

shack0315 2

Key to shack equipment (as of March 2015):

1:   2 x HD monitors; 1 x 4:3 monitor (all run from single PC).

2:   Icom IC-756pro HF/6m transceiver.

3:   Datong FL2 audio filter (used on SDR receivers).

4:   MFJ-1026 Signal enhancer and phaser.

5:   Creative Soundblaster Live! 24bit USB soundcard.

6:   Comet CAT-10 QRP ATU covering 80m-6m

7:   Trust 5.1 speaker system (using as a 3.1 system)

8:   Griffin Powermate USB controller, used as a VFO spinner for the SDR receivers & mounted on a scanner stand.

9:   RP6S 50MHz preamplifier

10: Zurich 25A linear PSU.

11: RFSpace SDR-IQ 0-30MHz SDR receiver.

12: Vibroplex Brass Racer twin paddles.

13: Laptop running ADS-B or HFDL/ACARS decoding software.

14: Antenna selection matrix.

15: Communications speaker, used as secondary audio output for SDR receivers.

Out of shot: Funcube Dongle Pro Plus 150kHz-2100MHz (approx) SDR receiver; 2 x RTL R820T2 SDR dongles; Various portable SW receivers, other Morse keys etc and Kenwood HS5 communications headphones.

Below are some images and info about the newest equipment in the shack:

The Griffin Powermate is a very useful accessory. It is normally used by video or audio editors so they can quickly scroll back and forward through a track. I find it very useful as a replacement for the traditional VFO ‘spinner’ which usually found on amateur radio transceivers or receivers, but absent on the majority of SDR based receivers. With the Powermate, I can tune up and down the band with ease - this is especially useful in a contest scenario, or if I am bandscanning.

Powermate

The Comet CAT-10 is an ATU designed to be used for a receiver, or a transmitter/transceiver up to a maximum of 10 watts output. Inside, the ATU is well constructed with airspaced variable capacitors and a solidly wound, multi-tapped coil. The ATU covers from about 3.5MHz up to 50MHz. As there appears to be spare contacts on the switch, it may be possible to add extra inductance to get it to cover 160m too. Seems to work well on receive - it will tune my attic dipoles on all bands down to 40m (it will peak on 80m, but the antenna is woefully short, and deaf, there)! It is much better quality than the Vectronics ATU I used previously, although that did have a few advantages, like switchable inputs and a bypass switch. This features neither! It is always in circuit, so requires retuning whenever a new band is used, even if the antenna is resonant on that band.

IMG_9785
atu 0414

Quite by chance I managed to pick up this Spectrum Communications 6m preamplifier. I was in the right place at the right time to get it at a very good price. For some time I had been looking at getting a preamp for 6m as I felt I was missing out on some weaker signals. This preamp does a great job on the IC756pro, giving a real boost to the wanted signal whilst not adding too much extra noise - exactly what you want from a preamp. It would be better sited at the antenna feedpoint, so that any feeder noise is not amplified. This is as good as I am likely to get in that department as this is fed from my HF OCFD.

rp6s

This is my homemade antenna selection matrix. The box is made from thick walled aluminium and is fitted with 8 x SO239 sockets (7 of which are currently in use). The socket marked ‘VHF Yagi’ is not currently in use, but is required for a future project (can you guess what that might be?). Each patch lead has an identifying label, plus a ferrite choke. I am able to run any antenna to any receiver without the need for antenna switches.

ae box

Morse Keys in use in the shack. The first is a Lionel Co. J-36 bug made in 1942. The second is a Vibroplex Brass Racer. This version had a built in electronic keyer (which are nearly always non workers when the key gets to this kind of age - 20 yrs plus). As the keyer was non functioning, I removed it and reverted it back to being a plain Brass racer. Lovely key, uses magnets for tension instead of the usual spring arrangement.

J36 brass 2

ANTENNAS CURRENTLY IN USE:

In the Attic/Loft/Roofspace:

The main antenna now is a home brew parallel wire dipole for 15, 12, 10 and 6m, due to a move of QTH. I also have an Off Centre Fed Dipole roughly cut for 20m, and fed via a 9:1 balun in the attic (home brew), a 1/4 wave groundplane antenna for ADSB on 1.09GHz (also home brew) and a 2 element circular polarised ‘Turnstile’ for receiving weather satellites on 137MHz. It also works quite well on 2m, considering the unusual arrangement. There is also a vertical tribander white stick antenna that covers 6m, 2m and 70cm, which works very well.

dipoles

The ADSB antenna - made from the inner conductor of an offcut of coax and soldered directly to an SO239 socket. This is a quarter wave ground  plane antenna with 8, instead of the usual 4, radials. The radials are sloped at 45 degrees to give a better match to the 50 Ohms.feeder. This is a further improvement over the prototype I used. I now have a range of upto 200NM.

adsb 1

The Weather Satellite antenna - This is a ‘Turnstile’ antenna which consists of 2 dipole elements a 90 degrees to each other and fed in such a manner as to give the antenna RHCP, or Right Hand Circular Polarisation, which is the type of polarisation used by both the NOAA APT weather satellites and the amateur radio satellites (and ISS). To increase the gain of the antenna, a pair of crossed reflectors are added. This antenna works very well, although this design does lack coverage at very low angles. A QFH works better in that respect. This design of antenna can be purchased cheaply (25 or less) from a European constructor/seller on eBay.

adsb 2
turnstile 1 turnstile 2
colinear

This is an image of the collinear triband vertical antenna that I occasionally use. It stands about 1.6m high and covers 50, 144 and 430MHz. I have mounted this in the attic, along with the other antennas described. The 6m coverage is adjustable, courtesy of a tunable radial. It was much cheaper than other branded makes. Seems to work fine, I have heard Brazil on 6m, so it can’t be doing too bad! It is noisier than the OCFD outside, but that is to be expected given that it is sat just 40 or so cm above all the house wiring (which is on the attic floor, and below the antenna). I have also installed a home made 6m wire delta loop, based on a design I saw on the internet, which is sloping at 45 degrees due to its physical size. However, the SWR is very good and it seems to work well, although it is noisy, but not as noisy as I would have expected.

In the Garden:

My Wellbrook ALA1530 active loop antenna (ALA1530) has been moved from the very poor location at ground level, tied to a fence in the front garden, to a much better location (in the rear garden) and as far away from the house (and other houses) as I can get it. It is now about 22m (75 feet) away from the house, our Plasma TV and computers, etc. It is about 4m (13 feet) up and attached to the fence with a wall bracket, and the 50mm aluminium mast is sunk into the ground by about 9 inches for extra protection against the high winds we sometimes get as the location is quite exposed to the West and South. The loop is still not turnable and there is a large amount of noise on the lower bands, from about 5 MHz down to LW. This seems to be mains borne (from the sub station behind the antenna, and also from either my own house, or the neighbours house - noise travelling up the mains. I don’t think it is PLT interference, but it may be). Luckily I can reduce this to a manageable level with the MF1026 and my attic wires. I can rotate the loop by hand, if really necessary, but of course I need to know which direction I require it to face before I set off down the garden. Not ideal, but a lot better than where it used to be. The ALA1530 is showing a good, low noise level from 10 MHz upwards, and is receiving well. 

sm-20140716_133318 ala1530-0414
sm-20140716_133332 sm-IMG_0813

My modified OCF dipole. It is just over 20m long, but has a 3rd leg which gives it improved performance on the higher bands (including 6m). The antenna is made from my existing OCF,balun (from M0CVO), but the wire elements have been replaced with ex army kevlar wire (made by Racal).  Having done some tests, I can confirm that it works very well on 6m - it has a lower noise floor than my attic dipoles and the signals are stronger (not every signal, but the majority seem to be a good 1-2 S-points (in some cases more) up. Coverage of the UK on 6m has improved too. As for HF, it doesn’t work as well as it could due to the lack of height, but it is not deaf by any means. Overall I am very pleased with the performance of this antenna. Below are the SWR figures I recorded (without ATU, of course): Will tune all bands with an ATU, but will work on 6, 10, 20 and 40 without the need for an ATU.

67 feet OCFD VSWR Measurements (0315)

BAND

SWR

6m

2.1 - >3:1

10m

1.3 - 1.6:1

12m

3:1

15m

>5:1

17m

2.9:1

20m

1:1

30m

3:1

40m

1.6:1

80m

Too high to measure!

The OCFD, on it’s new mast (extends up to 10m, but currently sitting at about 6m)

mast 3 mast 1
mast 2
mast 4
choke 1

The OCFD, looking at the feedpoint. The second image shows the common mode choke (a design by GM3SEK), designed for the higher bands (14-30MHz)

My old HF antenna was a 20m long OCF (Off Centre Fed) Dipole in an inverted Vee/L configuration due to the length restriction of the garden. The apex of the OCF was 10m above ground. I purchased this antenna as a ‘short’ OCF that covered from 20m thru 6m, from M0CVO antennas. See my other shacks page for diagrams and details of the layout etc. This is the same basic antenna that is in use now, except for my modifications!

[Home] [My Shack] [G4UCJ Shacks] [Classic Gear] [DX-ing] [DX Stats] [Digital Modes] [Contesting] [50MHz & Up] [Weather Sats] [Beacons] [Morse Code] [B'cast Radio] [Clubs] [Articles etc.] [Links] [Family] [Guestbook] [RA1792]