In response to the current use and mis-use of 50 MHz.
This is a draft executive summary from the archived material pertaining to the submission written by local 6M ops in 1989 and sent to the WIA in January 1990 for forwarding onto the ACA w.r.t. restoring some operating priviledges to the 50 MHz band removed in January 1964.
Background (The Broadcast service utilising Channel O was scaling down transmitters and translators).
CH0 Melbourne and Sydney closed. CH0 Brisbane moved to Toowooomba.
Points.
Page 1 (a)
To conform more closely to the international amateur operations....segment requested 50.050 to 50.200 mHz.
Page 1 (b)
Operations on a shared non-harmful interference basis to CH0 TV services...
No amateur service within 120k of a CH0 transmitter.
60K from a translator
60K from an Input RBR (rebroadcast receiver).
Page 2......nearly all overseas long distance operation is centred around 50.100 MHz.
Using SSB and CW modes.
Summary ...
At present with the rise in the sunspot cycle and increased solar activity the potential for long distance communications around 50MHz is enhanced.
Radio operators in Australia would like to participate in the coming cycle possibly for a once in a lifetime enhanced long distance 50 MHz communication conditions.
Enhanced F-layer propagation and TEP are essentially daytime/evening phenomena.
The operating hours of Channel 0 TV are also daytime/evening.
As a result operators on East Coast Australia cannot transmit during TV hours.....
Proposed 50.050-50.200 to conform with International Operating practices.
Amateurs occupy band less than 5% of TV operating time.
IN GENERAL:
The band will only populated under enhanced F layer and TE F layer conditions and during these periods, interference between international broadcasting services is very high this masking any amateur intrusions onto the Australian TV services.
AMATEUR MODEL
Based on a suburban amateur 6M station
with a mast height of 10 metres interference will be minimal.
ERP 400 watts.
Affording a protection ratio of 35dB.
MODE OF OPERATION
E layer propagation was only referred to in the context that during enhanced F Layer conditions E-layer is suppressed and the periods of time when F layer conditions were expected were outside of the E layer season (Summer) and were normaly within a month of the equinoxes.
And as such local propagated signals causing interference to interstate CH0 TV was unlikely.
A full copy of the Summary is available on request..
Summary of points 6M Submission to ACA 1989
Re: Summary of points 6M Submission to ACA 1989
The citing of content of a submission to the then ACA should not imply any particular status.vk3six/a wrote:In response to the current use and mis-use of 50 MHz.
...
None of the quoted content is actually explicitly incorporated in the current LCD, and has no regulatory status of itself. It might have been part of the considerations in making rules, and that may be interesting in understanding why rules were made, but anything that isn't part of the rules is not binding on anyone.
Promulgating 'gentlemen's conventions' is going to be a problem whilst the peak body (the WIA) is seen to not represent the majority of hams and the current band plans are out of touch. Any attempt to encourage acceptance of such conventions needs a softly softly approach... but what I see in the forums here on the subject is a push by a few to represent rules to reserve parts of the band for their own perceived priorities.
Owen