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Since 15 years digital communication made possible contacts that could not be done before. This is true on HF and VHF. We would like to explore the benefits of digital communication in the UHF bands starting with the 70cm band.

What could we expect from digital communications on that band ?

- Tropo : the JT65B ot JT65C (and soon QRA64) allows a 6 to 10 dB improvement compared to the CW. So if you have a 30W transceiver, this is like if you had 120-300W (an average amplifier). Of course tropo conditions are very difficult to predict, ans are slightly different from what can be observed on 2m. Anyway, the gain provided by the digital modes should not be neglected.

- Aircraft scatter : This is not really a propagation mode, but the use of the reflection of waves on an aircraft to achieve a long distance QSO. The ISCAT-A or ISCAT-B modes had been designed for Aircraft scatter, and can be used even on 3cm or 1.3cm. Aircraft scatter allows QSO to be done up to 700-750km almost every day (all you need is an aircraft well located!).

- Meteor scatter is more difficult than on 2m (reflections are shorter and weaker), so the use of FSK-441 (and MSK-144?) is limited to shower peaks, but QSO in the range 1000-1800km are still possible.

For those who have no experience (even on 2m), we can provide basic help, or advise in setting up your own equipment. Skype is a good way to do this, but it can be done via email also.

Skeds can be arranged by :


- The 'chat' ON4KST in the room 144-432MHz.

- Email : f6kbf (at) free (dot) fr

- Skype : f6kbf78

- Phone : +33-6-60-48-63-28 (cellular phone)