# Redifon RMT1500



## Mayday (May 26, 2009)

Has anyone , just possibly got a cct diagram pdf of the Redifon RMT1500 transmitter.
I would dearly like to relate a story regarding the changing of the calling frequency bands,
I remember being advised that we needed to lose either the 4Mhz or 6Mhz bands but the actual solution was very much simpler.


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## Dimples82 (Aug 24, 2014)

Are you sure this was a "home grown" piece of Refifon kit ?
Ask this because it is not unknown for kit to be purchased and rebranded. 
Was This a SAIT Marine SSB Main Trransmitter Type MT1500 in mufti?


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## sparks69 (Dec 18, 2005)

Having once met one of Redifons's design engineers when he came down to investigate my complaints about a BP River boat on its maiden voyage. I was informed that our full set of Radio room gear was 100 % Crawley (??) made and not re badged.
My main complaint was that the R551 Rx was little better than a Marconi A-Lert on MF ! He admitted it was not the best but met type approval.
Nice guy & I learnt a lot that day. It's in my diary as a good day.
Mind you I had never seen SAIT gear..................


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## Dimples82 (Aug 24, 2014)

I know this happened at Kelvin Hugh's with their Pentland Alpha & Bravo TRx these were replated Racal products, as well as their Foreland VHF'. 
Marconi were not above this practice either. As sub contractor I remember I was told told to rebrand a VHS recorder with my companies badge etc, this was a practice I did not agree with, so in the end the prime contractor had to do the deed.


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## Wismajorvik (Dec 29, 2011)

Redifon marine kit was manufactured by Redifon Telecomms division in the Broomhill Road, Wandsworth factory. The Telecomms division manufactured a large range of equipment including the infamous “third method” SSB transceivers.


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## Ron Stringer (Mar 15, 2005)

Please tell u more. What were “third method” SSB transceivers and why were they infamous?


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## Wismajorvik (Dec 29, 2011)

The two principal methods of SSB generation are the filter system, (most common) and the phasing system. The third method was invented by Weaver in the mid 50s and as far as I am aware only Redifon used the system in their transceivers. The radios were often referred to as mickey mouse sets by military users. Plenty of info on the web regarding how the system works. Later Redifon equipment used the filter method.


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## Wismajorvik (Dec 29, 2011)

The original query makes me think that this tx could have been rebadged as Redifon transmitters were prefixed “G”, receivers “R” and transceiver “GR”. The G341 was the only marine tx I recollect.


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## pippin (May 13, 2008)

Thanks for the enlightenment - I assumed that first method was a crystal, second was a TRF and third was a superhet.
Now, what were those crystal rings for?
I really must keep up-to-date on technology!


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