160m loft antenna diagram

This is a diagram showing the arrangement of my 160m loft-mounted antenna. The ground connection is made to a hot water tank (copper) next to the upstairs shack. It connects via copper pipes in the house to the external ground and works very well. The top capacity hat should be as large as possible but in my case is just a couple of horizontal wires around 1-2m longh in each case hung horizontally in the top of the loft space.

160m JT65

My 4 year old grandson having gone home now, I have my shack back again so am able to play amateur radio again. I've several things to catch up on including:

1. Trying for a first 160m JT65 QSO.
2. Measuring the performance of my ST-3 JRC headphones that AA1TJ managed to find for me recently.
3. Another over-the-horizon 481THz test looking for G4HJW's beacon and my own.
4. Testing my iPod Touch SpectrumView application with an external audio input.

This evening I have been copied by G4HPW (87km) on JT65 on 160m but no 2-way QSOs with this mode are in the log yet on topband using my compact loft antenna.

10m good despite the flare

Today all the propagation forecasts were showing poor conditions on HF. Despite this, 10m was well open this afternoon to the Middle East, Africa and South America with good signals received. My only QSO so far has been with JY5HX when running 5W CW here.

The lower part of 10m had several Russian (?) CB stations including one operating almost on 28.060MHz, the CW QRP frequency. Use it or lose it folks.

160m JT65

As I appear to be having some success with WSPR on topband, I have decided to try JT65 on the band to see if I can manage a few QSOs.

UPDATE: after calling for around 15 minutes I gave up!

My 160m WSPR analysis

Since erecting my tiny 160m loft mounted vertical this last weekend I've used it on WSPR a few evenings with great success. The following tables show the unique reports received and sent on the band using (mostly) 5W. Most stations copying me can be copied here, despite the horrendous noise issues on the band at night.

160m WSPR reports received

160m WSPR reports given

So far, reports have been received from 9 countries with best DX being 1007km. Not bad with an antenna which is essentially a 1m long coil, a couple of top capacity wires and about 3m of feed wire from the loft to the upstairs shack and tuned against my central heating system copper pipes as a ground.

Elecraft KX3 manual

The soon to be released KX3 QRP transceiver

The preliminary version of the owner's manual for the latest Elecraft KX3 12W all mode 160-6m SDR portable transceiver is now available. The product is expected to ship very shortly now. Reading the manual it is clear this is a VERY impressive radio packed with features and facilities. Initial reports from field testers confirm performance of this little radio is up there with the very best, and all this in a size not much bigger than the control head of an IC703.

VLF test by OE3GHB

OE3GHB's VLF loading coil and transmitter

OE3GHB has reported on his 8.97kHz VLF tests this weekend. He was copied by several stations in W.Europe. Gerhard's signal was clearly detected by OK2BVG, DF6NM, DK7FC and by Paul Nicholson in Todmorden. There was a trace seen by G3ZJO. At the moment my VLF system is out of action so I was unable to take a look. The picture shows Gerhard's enormous VLF loading coil. Antenna current was around 600mA and his antenna was a vertical on an 18m fibre glass pole with a 100m horizontal top wire with 600pF capacitance.

Mixed results on 160m

The small loft antenna for 160m has produced some impressive results tonight with spots from all over NW Europe of my QRP signal. Best was GM4SLV in Shetland at 5W and OZ7IT at 2W.

But the real reason for erecting the antenna was to allow QSOs on QRP AM over a 3km path to G6ALB so we could use topband for a talkback link when doing other tests. Now, at 9.30pm we went onto 1.973MHz AM to see how easy it would be. It wasn't easy at all! In fact it was very hard work copying even a few watts of AM. The killer is the noise floor that is around S9 both at Andrew's home and mine. On WSPR, with its much narrower bandwidth this is not such an issue, but on AM it ruins the band for what we'd intended. There is no way that 0.25W of AM would make it, certainly not easily with simple rigs as we'd planned. 10W would be OK, but that defeats the purpose. On 70cm AM (yes AM) we had armchair copy between us with about 1W. On 160m FM it was better copy until we dropped the power down and the signal was drowned by the QRN/QRM.

So, what will we do? There is now no point in continuing with the 160m AM transceivers as this isn't going to work at our noisy QTHs with QRP over 3km, sadly. The most probable choice will be 6m AM using my SixBox rig at my end.

The lower HF bands like 160m are radically different from 30 odd years ago when the noise floor was some 20-30dB lower.

160m loft antenna erected

160m loft antenna

Today I erected a small loft antenna for 160m use. The prime purpose is to allow me to test my QRP AM transceiver (that is under construction) with G6ALB in the next village. The idea came from an old RSGB book called, "Practical Antennas For Novices" by John Hayes G3BDQ. It consists of a long coil wound on a PVC pipe about 1.5m long with a couple of wires along the top of the loft as a top capacity hat. In John's design he used 21mm pipe but I chose 32mm instead and my inductance measured 590uH. Just a little more inductance in the shack was enough to make the antenna resonant when tuned against ground (my copper hot water tank and pipes in the house). Now it is time to find out how well (or not) it works. Incidentally without the additional loading in the shack it was a good match on 40m and 15m too.

UPDATE: My first 2 WSPR reports on the new (indoor) antenna were from OZ7IT at 853kms! The antenna must work, HI. Shortly after PA0A spotted me.

DMR products

My old company, Sepura, entered the Digital Mobile Radio market last year (as an addition to the TETRA products they already design and make) and are, as we speak, designing DMR products for sale in the near future. In recent days they've had a wake-up call from their major competitor Motorola in the form of two new DMR radios that set the benchmark. See http://www.motorola.com/Business/XU-EN/Product+Lines/MOTOTRBO/SL4000+Series/SL4000_SL4010. These look very attractive products and I am glad I no longer have the task of trying to beat them! Instead I can tinker with lightbeams and VLF.