50 nanowatts ERP tests on 70cms FM

This afternoon I did a quick test using my signal generator on 432.975kHz FM using my V2000 vertical. I put up a 50nW ERP FM signal with a 1kHz tone and looked for the RX signal on my little VX3 hand portable with its tiny helical antenna at my old QTH some 300m away from the new location. Although unable to copy the signal downstairs, the signal was S3 in the old shack upstairs. Based on this test with a pretty inefficient RX antenna, I think the 10nW signal would be copyable around 1-2km away with a mag-mount on the car. It goes to show how far QRM can travel.

Back on 472kHz WSPR and 8.97kHz

This afternoon, I put my earth-electrode antenna in the garden at the new QTH with the remote electrode against the far fence and the local ground connected to the mains ground in the shack. Check your mains earthing before trying this. Separation is about 15m i.e. a little less than at the old location. On 8.97kHz the current into the ground looks about right and the TX current similar to that at the old QTH. On 472kHz the match seems a little different but I have had several spots from G6AVK at 78km when using low milliwatts ERP. I need to optimise the match on 472kHz.

I am now going to try the earth-electrode antenna on 160m and 80m. All being well I'll do a remote RX test on 8.97kHz to see how my VLF beacon compares.

Shack pic

Well today I completed the set-up of my "building desk" in the new shack. After several weeks out of action, I am now ready again to start building gear. For the first time my desk for building kit is in the same room as the operating position, so I can readily test gear "on-air" by simply connecting a coax cable or wire. This image is not very good quality I am afraid.

Late summer Es on 6m

It is getting later in the sporadic E season but there are still plenty of openings to be enjoyed. As I have yet to erect any antennas for the HF bands at the new QTH, I have been listening and working stations on 6m. This week without much operating time I have managed to find a couple of Es openings that have allowed me to work into HA, I, EA5, EA6 (Menorca) and EA7 on 2W SSB or CW to the V2000 vertical.

Using my 3G dongle to provide an internet connection (roll on Sept 2nd and my Virgin Media connection - I hope) I've also been WSPRing on 6m but so far just a few UK spots received.

Our windmill

Just across our front garden wall we have a windmill that is almost 200 years old. It is currently undergoing a complete renovation with new cap, 4 new sails, new external rendering and lots of work inside too. Today, a 60 ton crane lifted the newly renovated (6 ton) cap onto the top of the windmill.

In the next couple of months the 4 sails go back on. The video was shot out of my lounge window today. When fully restored it will be well worth a visit as is a visit to our local museum next door.

From an amateur radio perspective the windmill will be a perfect aiming point for optical comms as it is about 20m from my shack. I suspect it will act as a good reflector for microwaves too.

See http://www.burwellmuseum.org.uk.btck.co.uk/StevensMill for more information.

More antenna progress at the new QTH

After having our little grandchildren stay for 6 days (without their parents) the new home has now returned to normal (i.e. tidy) and all the toys have been put away, mine excepted! So, apart from sorting out and decorating the old QTH, my thoughts are increasingly turning to the autumn ham projects again.

I've just collected my Par 10/20/40 end-fed HF antenna and a 1m solid copper ground rod from the old QTH with the aim of erecting the former and pounding in the latter in the next few days. The Par antenna will allow me to get active on some of the HF bands. The earth rod will form the far end of my new earth electrode pair "antenna" which will be used for a series of tests on 8.97, 136 and 472kHz from the new garden. My 8.97kHz beacon can be fired up in QRSS quite easily so RX tests out in the fens can start as soon as the earth-electrode antenna is ready. It will be fascinating to see how this compares at the new QTH.

My big wheel for 2m has still to be procured or made and erected. When this is in place I shall try some QRP weak signal work as mentioned before.

Something else I want to do is some tests locally on 6, 2 and 70cm using a signal generator connected to my V2000 antenna. Tests with G6ALB suggest just a few uW are enough to reach the next village. So I was wondering what the coverage to a mobile would be like locally with, say, 10uW from my generator? A drive-around test in all directions might be fun.

We are still waiting for Virgin Media internet and home phone access though - due Sept 2nd - to allow proper WSPR tests to begin. I bought a 3G wi-fi dongle with 3GB of data which is being used as a stop-gap. WSPR is my mode of choice when testing new antennas or new set-ups as the internet database (near instant) feedback gives a very good idea of how things are working.

Belgium on 472kHz

Rik Strobbe ON7YD reports that some Belgian amateur classes (holders of a HAREC licence) now have access to the 472kHz band with 5W EIRP and without mode restrictions. Unfortunately Rik's PA failed on TX on the new band and is having to rely instead on a 6W transverter for now with just 20mW ERP.

V2000 erected and first QSOs on 6, 2 and 70cms from new QTH

On Tuesday I completed the erection of my tri-band colinear at the new QTH and carried out some tests over a 3km path to G6ALB to see how results compared between my old and new QTH on 6, 2 and 70cms. I was expecting results "on the hill" to be somewhat better, but in actual fact over this short path the results were identical within the limits of experimental error. Andrew put in various levels of attenuation to see how low he could go and still copy me. On 2m for example he could put in 43dB attenuation and still just copy me. 43dB is an attenuation of 20000 times suggesting just a few uW is enough to cover this distance.

Yesterday morning I was able to work through the Welwyn Garden City 70cm repeater, although conditions were up a bit. Last night I worked several I and HA stations on 6m SSB and CW during an unexpected Es opening, getting good reports with my 5W.  Conclusion so far: the antenna works fine.

I am now considering that big-wheel for 2m on the same mast. I am looking forward to working some SSB/CW stations again on 2m.

Assembling the new shack

Today I started to collect all the remaining kit from the old building shack and set it up in the new QTH.  The large pieces of test gear are the easy bit. It is all the boxes and bags of "these might come in handy some day" components and crystals that are the problem. Also wire: I have so many reels of "useful" wire! My plan is to continue this over the weekend and get most of the useful stuff moved and other, less useful, kit boxed and stored in a box should I ever need it.  I am really hoping that I can be a lot better organised going forwards. Once I start an electronics building project the workbench goes from orderly to chaos very quickly!

When I was an RF engineer (not a very good one BTW) we used to keep resistors and capacitors in little open topped brown envelopes in a box on the bench. This worked very well and was easier and less space intensive that racks of storage drawers. I may go back to this for the more common non ESD sensitive components.

Moved to new QTH

Although still without internet and phone - thanks Virgin Media - we have now moved to the new QTH. I have still to erect my V2000 vertical but hope to have this up over the weekend. Amateur radio is taking a back seat whilst teething troubles with plumbing and electrics are sorted.  Until we get internet at the new QTH these blog postings are likely to be few and far between.