AmateurRadio.com

Cambridge Punts

Every Tuesday I travel into Cambridge for my weekly U3AC course called “Maps in the Computer Age”.  I am enjoying the course very much.

Usually I drive to the “Park and Ride” car park at Newmarket Road and get the bus into town. The U3AC course is at the U3AC headquarters in Bridge Street, which is about 30m from where the punts are on the River Cam.  At this time of the year the punts are quiet. Come the summer and this spot is very busy. Cambridge has lots of foreign visitors when the usual students go home. If you see a foreigner with a map wobbling along on a pink bicycle it is a good idea to be well clear!

Round Church – very old building

From the punt place you can punt right up via St John’s, Trinity, Clare and Kings College.  Kings College Chapel is lovely from the river.   The secret is not to leave your punt pole behind. It is easily done. Luckily the Cam is not too deep. If you prefer, you can pay someone else to do the punting so you can just sit back and enjoy a timeless Cambridge moment.

Bridge St,  Cambridge

Some of the views have not changed much in centuries. The Backs in Cambridge are very beautiful and it is little wonder people travel from all corners of the Earth to visit this beautiful centre of learning.  It is all too easy just to take it all for granted. Certainly, when I worked in the city, I did.  Now being retired, I properly enjoy it. It is still a very beautiful city with fine very old buildings and the River Cam winding its way up behind the colleges. If you have never been, you are unlikely to be disappointed.

Many years ago I was with a friend who parked at the multi-storey car-park just off Bridge Street. We worked a VK6 (S.W. Australia) from the car on 10m SSB.

See http://www.southgatearc.org/news/2015/february/ht_of_the_future_at_orlando.htm#.VNi6BC4WKPc .

Southgate News reports that Bruce Perens K6BP will be demonstrating a handheld platform that can cope with many modes at VHF/UHF at the Orlando Hamcation in Florida. This looks like a demonstrator at 100mW RF. With SDRs, quite a flexible, and low cost, architecture is possible.

I wonder which of the “big names” will be first to market with a real SDR design? This could enable them to sell very low cost units, but maybe they would rather shaft us and make big profits?

As I have mentioned before, I am a rare repeater user, partly because my voice is so poor currently and I don’t find operating through repeaters that satisfying. Each to his/her own and if this helps you enjoy the hobby go ahead!

At the moment it is far from clear which form of digital repeater will win: there are several competing digital standards and all have their advocates. For now I shall sit back and wait. A bit like the video standards war in the 1980s, the best system may not win. Let’s see. Up to now I have only used FM repeaters.

When I do use voice I use SSB, FM and AM. All modes have their places on our bands. SSB is good on the crowded HF bands, FM useful for nets on VHF, and AM rigs simple to build and there is space on all bands from 10m upwards for all analogue voice modes. A well designed AM rig should occupy less than 6kHz, far less most FM transmissions on our bands. 10m AM, just above 29MHz, is a great mode. I have worked quite a few stateside stations on 10m AM. And I have only used QRP AM.  Let no-one tell you AM is a dead mode!

Today I checked the sensitivities of my FT817 and FT817ND using a loaned signal generator. Although about 10dB deaf at 472kHz (expected) both were easily able to copy down to -127dBm on CW on all bands to 70cms. -127dBm is as low as the generator would go.  I could have added a 10dB attenuator, but did not.  I also managed easy access of GB3PY and GB3OV 70cms repeaters at the 500mW level into the V2000 vertical.  My conclusion is things are OK at my end and I wonder if G6ALB has some additional cable loss at 70cms at his end (water in the feeder?).  My antenna has been up for about 2 years whereas his has been up for around 20 years.

From my bank statement I see my 40m Pixie kit from China, that has shipped, cost a little over £7. This includes all parts including crystal and PCB. At this price it would be hard to buy the individual parts. I very much want to build this as it will be the first amateur radio construction here in a very long time.   It is sufficiently simple and low cost that I should manage it, even if I am a little clumsy still with the soldering iron.

 No doubt Andrew G6ALB (3km) will help with a first test.

Again, from Steve G1KQH, a link that may well be of interest to UK readers:

Did I send you this one Roger?

http://www.gridwatch.templar.co.uk/

73 Steve
http://www.g1kqh.talktalk.net/

Many times we hear that closing old and polluting power stations is putting us at risk of power blackouts. Check the electricity capacity yourself.

In the left hand corner you can also check for France.

See https://www.gov.uk/government/consultations/radio-equipment-directive-proposal .

Quite soon this new directive will apply in Europe including the UK. Many low cost modules may cost a little more as receivers will need to be more carefully designed to meet RED requirements. It is likely that more stringent RX parameters will have to be met. I wonder if some of the very low module costs are as a result of the dumping of old stock? This could well impact super-regen receivers that are sensitive, but not very selective. Although fine in some markets this type of receiver is less than ideal in a very busy ISM band where they could easily be blocked.  Listening around 433.92MHz recently, very many ISM devices could be copied.  One of my old colleagues is involved in international committees working on RED.

The “internet of things” means very many devices will include radios in future, such as a basic internet terminal in washing machines or RFID tags.