AMVK

Just some vacuum tube fun..

Hi,
Not a whole lot happening on the site. I have yet to get the AWA P5 into converted and operating condition. Usually, I am on 7.125 AM on Saturday mornings at 8:00am EST(2200 UCT), although recently distracted by renovations..

You can email me at [email protected]

Hi. Sorry for the silence. We have someone working on the logo for the new site, and a web presence so hold fast!

AM in a Digital Age
Stephen Coleman VK2ASC

Recently, a number of amateur operators who have a particular interest in heritage operations and in the AM mode generally expressed some concern at the ZL2SEA proposal to use 7.123 Mhz for automatic data modes (reported on the WIA News on 31 March 2019).

The concern has arisen because 7.125 MHz has for many years been considered to be the AM calling and net frequency on the 40 metre band and is the frequency used by the VK2BA AM Net on Saturday mornings at 22:00 Z. The net was named after the callsign of David McNaughton who started the net and who became a Silent Key in February 2015. David’s widow, Jenny qualified and is the current holder of the callsign.

You may be surprised to hear that there is a lively group of amateurs who restore and use repurposed vintage broadcast equipment and valve based or hybrid amateur equipment for AM communications – particularly on 160, 80 and 40 metres.

AM receivers, particularly vintage receivers, cannot easily null digital signals within their passband, and such signals can render that frequency unusable for AM. This is a particular issue when much of the military and commercial repurposed equipment is crystal controlled, and there is limited or no flexibility to move within a band.

Part of the interest for those of us who operate AM gear is the heritage value in the restoration and use of ex-commercial, military and amateur equipment made in Australia (yes – we made very good radios once), in Britain, the US, Russia and elsewhere. Much of this equipment is impressive in size and in how well it performs, even by today’s standards. In addition, there are many in the AM group who enjoy constructing CW and AM transmitters and TRF, regenerative and superhet receivers. There is little that sounds as good as a valve (tube) based receiver and a good AM signal.

It is hoped that the hobby is diverse enough, even with the limitations on available spectrum, for there to be some sensitivity applied to band allocations so that everyone can enjoy their particular part of the broad hobby of amateur radio.

As a result of these considerations, a few of us have formed the AMVK group. It has a short manifest which it is hoped will be of interest to Hams generally, but particularly to those with an interest in AM and “boat anchors” as well as in home brewing AM gear. The aims are modest, but it
is hoped that they will be considered when Band Plans are being formulated. If anyone is interested in putting their name to the proposal in the manifest, please contact me on [email protected]

If you have an interest in “boatanchors” or if you have an AM mode on your transceiver and would like to chat, call in to the VK2BA AM Net on Saturday (and Wednesday) mornings at 8:00am EST (22:00Z).
73
Stephen Coleman

AMVK is a group of amateur operators*, in Australia, who use and wish to ensure the preservation of AM as a legitimate and useful mode of emission:

AIMS:

1.Ensuring the preservation and continuance of AM as a legitimate mode on each amateur band;

2. Preserving and using historical broadcast and amateur equipment and constructing new AM amateur equipment, in accordance with the regulations applicable to amateur service, in order to serve a valuable and enjoyable cultural function which is part of the historical
and ongoing development of amateur telecommunications;

3. The recognition and allocation
by convention in any WIA or IARU sanctioned Band Plan, or by regulation if appropriate, of one calling, and one net frequency, in every HF amateur band, 6 and 2 metres, for
the primary purpose of AM
communications.

4. Promote the addition of AM as a
notation as a permitted mode in any Band Plan, in those parts of the band which are set aside for telephony;

5. Promote a specific note in any Band Plan, or in any relevant regulation, that digital modes or suppressed carrier telephony should not operate within 6 KHz either side of the AM calling / Net frequency on each band;