80-Bus News


April–June 1982, Volume 1, Issue 2

Page 16 of 55


DH replies:

Although I agree with almost everything Pete says, I had to come back on this didn’t I? I’ll comment where I think clarification is necessary on a paragraph by paragraph basis.

Yes, the times they are a’changin’, as they say. As was pointed out in the last issue, the content of the magazine reflects the contributions made to it. If the majority of contributors have disks, then the articles reflect that. This is certainly the case at present, and we’d welcome any articles on either mini cassette systems or Uncle Clive’s microfloppies (when [ Ra. – if | they appear) to redress the balance. If you are using a data loading system which is fast and cheap then let us know. On the subject of sending us articles, can we have them in machine readable form if possible. We don’t mind either Nascom or Gemini tape formats, or any IBM 3470 (or is that 3740) compatible disk format, we think we can read most, either 5.25" or 8".

Now on to my article in the last issue ‘Breaking Computers’. As I think Peter realised, it was written ‘tongue in cheak’. Dave Hunt, him speak with forked tongue, etc. As to the ethics and legality of the suggestions I made, I hope I made it totally clear that they weren’t either legal or particularly ethical. Regarding the use of ‘linears’ when a cheap class C PA would do equally well if not better, it seems most of the linears come from Italy (surprise surprise, not the Par East). The Italians use SSB quite a lot and a linear is necessary for this purpose. You might like to note that it is legal to import them and sell them, it’s the owner who breaks the law by using them.

Pete attributes the frequency-agile channel changing idea to me. Sorry, that’s not correct, it arose out of a discussion with several interested parties over a year ago, and I don’t remember whose idea it actually was. Secondly, contrary to Pete’s comment, above, the port controlled channel selector was about the only ‘legal’ part of suggestions. My copy of MPT1320 dictates the frequencies to be used (spurii, RF power, and a lot of other things), but says nothing as to the physical changing of channels. So it seems to me that computer controlled channel selection is totally in order. A second point stemming from the MPT1320 spec., is that the rigs do not have to be certified by the Home Office. The supplier, importer, constructor or manufacturer simply has to certify that the rigs meet the spec.

When I first read Pete’s letter it was the next paragraph which prompted me to write a reply. I also had a couple of other letters on this point. Pete refers to a ‘glaring error’, now fair’s fair, you can NOW send data on 144MHz and above (although, as we shall see, this is not technically open to all Amateur Radio Licence holders). But at the time I wrote that piece, way back in February, the great February 12th debacle was about to break on the amateur radio fraternity to cause many whoops of joy, or wailing and gnashing of teeth, depending upon whether you had an ‘Amateur B’ or ‘Amateur A’ Licence. Anyway, up to that date, data transmission as such was a definite ‘no go area’ as the earlier schedule was then still in force. .

I won’t dwell on the ‘Great Home Office Cock-Up’, as a long discussion about radio topics, even about the wrong doings of those who consider themselves our masters and who know better than we mere mortals will ‘bore the bytes’ off the computer public who are reading this.

However, it’s interesting to note that the revised schedule of the 19th March still technically prohibits data transmission (and also, if interpreted strictly, now prohibits RTTY as well) by holders of ‘Amateur B’’ Licences. The classes of emission we are interested in, either automatic on/off keying of a carrier or modulating tone or a.f.s.k. (automatic frequency shift keying) of modulating tones, A2B, F1B, F2B, G1B or G2B, remain the domain of the ‘Amateur A’ Licence holder as it would appear that our friends at Waterloo Bridge House can’t tell the difference between morse telegraphy and data transmission. As the new classifications of modes includes the emission type ‘D’ this problem could be overcome by including the following modes in the amateur schedules for use by both ‘Amateur A and B’ Licence holders:

This is an OCR’d version of the scanned page and likely contains recognition errors.

Page 16 of 55