[Premium-Rx] Fw: Racal 177x PSU

[GandalfG8 at aol.com]

In a message dated 09/08/2010 22:30:51 GMT Daylight Time,  
michaelob666 at ntlworld.com writes:

> I  suggest that some of Nigel's comments are a little harsh.  There was 
in  
> fact quite a time span between the last of the valved gear (typically  
the 
> RA17) and the RA1772.  There were the rather poor performing  RA217 
series 
> in between, though I suspect that their problems were  more the trouble 
of 
> early transistors rather than of inherent design  defects.


----------------------
Hi Michael
 
I'm sorry but I don't think my comments were particularly harsh so  much as 
just being realistic.
 
As I said earlier I don't dispute Racal's technical excellence when it  
comes to the 17xx series but there must have been something  adrift with their 
production engineering at that time.
 
Although the 217/1217 series was indeed the immediate unfortunate attempt  
to produce a solid state RA17, the mindset still seems to have been well  
and truly stuck in valve age production techniques when engineering  the 17xx.
That there was quite such a time span between the RA17 and 1772 only  
serves to indicate just how far the Racal head was buried in the  sand.
 
That wiring harness might have been "a thing of beauty", just as any  
complex cableform might seem in its uninstalled, or even installed, state,  but 
the 17XX series construction techniques were archaic in comparison  with 
other contemporary manufacturers of professional receivers.
 
The Redifon R1001 I mentioned previously was far more typical of good  
production engineering of that period, high quality fibreglass circuit  boards, 
chassis mounted connectors for all the control and supply wiring  with well 
organised fixed wiring beneath the chassis, and separate coaxial links  
topsides for all RF and signal interconnects.
Watkins johnson was building the Quad8 and Quad8B at this same time and  
even the Marconi ICS3 hails from the same period.
 
Racal, for whatever reason, was churning  out SRBP circuit boards on the 
17xx series, a nice touch of domestic  radio thinking here, with that 
wonderful hinged arrangement and everything hard  wired to pins along the edges of 
the PCBs and all routed through one big  fat umbilical cable.
What's really sad is not that they couldn't have foreseen the  cableform 
cooking and deteriorating but that they decided on this form of  construction 
in the first place.
 
And, no, I'm not given to Racal bashing, despite what it might  sound 
like:-), and in other respects I was once as great a fan of the 17xx,  especially 
of the 1784 and variants, as anyone could be.
 
Technically it was excellent, perhaps not too surprising given Danny's  
account of the setting up procedure:-), ergonomically it was very nice to use,  
but internally it was not at all well engineered and my enthusiasm waned.
 
I accept that I'm probably out of step with much of the rest of the  radio 
world, but this does not rank as one of my favourites.
 
regards
 
Nigel
GM8PZR