JT65A

JT65A on the waterfall

Begin one for exotic modes, I have become interested in a mode known as JT65A.

From the wiki entry : -

"JT65, developed and released in late 2003 is intended for extremely weak but slowly-varying signals, such as those found on troposcatter or Earth-Moon-Earth (EME, or "moonbounce") paths. It can decode signals many decibels below the noise floor, and can often allow amateurs to successfully exchange contact information without signals being audible to the human ear. Like the other modes, multiple-frequency shift keying is employed; unlike the other modes, messages are transmitted as atomic units after being compressed and then encoded with a process known as forward error correction (or "FEC"). The FEC adds redundancy to the data, such that all of a message may be successfully recovered even if some bits are not received by the receiver. (The particular code used for JT65 is Reed-Solomon.) Because of this FEC process, messages are either decoded correctly or not decoded at all, with very high probability. After messages are encoded, they are transmitted using MFSK with 65 tones.
Operators have also begun using the JT65 mode for contacts on the HF bands, often using QRP (very low transmit power);while the mode was not originally intended for such use, its popularity has resulted in several new features being added to WSJT in order to facilitate HF operation."

Moon Bounce ey? Must be good! So basically the above means JT65A is a weak signal digital QSO mode with a highly structured QSO.

There are not many JT65A operators on 11 meters but I keep transmitting and talking about it on forums and more people are getting interested. I had my first JT65A RX on 11 meters a few weeks ago with my SSTV friend 310LA from Lativa, unfortuantly I was not around to complete the QSO. However, today I had a partial QSO with 161BD520 - Sergiusz over in Poland, thanks Sergiusz! Unfortuantely it appears there is a limit on the callsign length (6 characters) so not really suited for traditional 11 meter calls signs - i'll keep you posted on this one as the experiment continues.

The program I used for JT65A is JT65-HF which can be download here: http://jt65-hf.sourceforge.net/

Save the Radio Spectrum

Are you suffering from a strange-sounding interference to your FM radio, DAB radio, Taxi radio, Business radio (inc. shopping centre radio), Airband radio, Marine radio, Military radio, Amateur radio, Citizens' Band radio, or Shortwave radio?

You may be suffering deliberate interference (Spectrum Abuse) from a neighbour (or neighbours) who are using Power Line Technology (also known as Power Line Networking).

Are you using a power line network in your home?

Also known as : -

• PowerLine Telecoms - PLT
• PowerLine Networking - PLN
• PowerLine Adapters - PLA
• HomePlug networking
• BPL

Please consider removing them and replacing them with a Category 5 UTP or Category 6 UTP patch lead ('wired network cable')

Are you using the British Telecom BT Vision service?

 

If you use the IPTV package from BT Vision and you have installed the PLT devices, please consider removing them and replacing them with a Category 5 UTP or Category 6 UTP patch lead ('wired network cable').  If you wish BT Vision to do this work for you, then contact their Customer Services on 0800 111 4567 and request a wired solution.

Alternatively, you could use a TV solution from another supplier who does not advocate PLT!

For more information and advice on what to do in the UK visit :

Ban PLT website.

UKQRM

Radio Amateur M0MTJ

11 Meter International Digital Modes Group (IDM)

"IDM" for INTERNATIONAL DIGI-MODES group.

This is an initiative of Alex 104fdx104 and Eric 9ew001.

Data Modes on 11 meters are gaining popularity

The main goals of IDM are : -

• to promote digital modes on 11 meters
• to organise activities such as:

regular meetings on the air

digi-days

contests

digi-SOTA, and others.

A digital modes band plan have been discussed on their forum and for some time has been establish with respect to phone mode operators and the frequencies already in use.

IDM are affiliate member of EMU, giving them more visibility to attract new followers and members from around the globe.

The group is open to all and to join, all you have to do is contact them by PM on the forum or by email to:

IDMdxgroup@gmail.com

There is absolutely no fee to join and all they ask is that you use your new IDM call sign as much as possible on the designated frequencies. The fact of having an IDM call sign will also greatly facilitate the validation of logs for the contests.

IDM PSK Challenge 18 July to 24 July 2011

Currently taking part in  IDM PSK Challenge 'contest', propogation conditions have not been very good this week but had a few contacts into division 14.   You can't beat a contest for sharpening your skills and getting to know your radio and software better.

I also joined the IDM group last week, so look out for me on the above frequencies, usually around 27.740 USB as 26IDM010, next post will be more about the IDM group.