[Premium-Rx] Racal RA1772

[LaverdaOrange]

Hello All

I had a good suspicion that Pat G3YFK could not resist throwing in some sage commentary on this subject!!

And rightly so, as Pat is too modest but I will say without hesitation he has forgotten more than most of us will ever know about this era of Racal receivers.

I was lucky enough to have Pat go through several of my radios many moons ago much to my delight.

I was a dumb cluck and passed on a nice RA1784 some years ago---but as most of this list knows, I am pretty much out of the HF game after 40+ active years, but I sure remember all the jollies I had with this gear.

Lastly, if I had just one only Racal RX to listen too, reliably, and still easily available, it would be the 1772 .

John England

San Jose, California


On Aug 8, 2010, at 4:30 PM, Pat1McA at aol.com wrote:

> Hello Alberto,
> 
> After repairing over 20 RA1772s and over 45 RA1792s I think that I can  
> comment on this subject.
> 
> The RA1772 appears to have been designed, at the time, with little  regard 
> for cost saving.
> There is a reason for this. After the valve/tubed RA17 receiver, Racal  was 
> struggling to produce a comparable solid state successor, in the event they 
> produced the transistorised RA1217 - which turned out to be  a disaster in 
> terms of performance.
> I remember visiting Portishead Radio, in those days GRL (1612kHz), but  
> later as GKA/B etc, around 1969, when they had replaced the RA17s with RA1217s  
> and the Operators were NOT happy at all !
> The general performance was so dreadful that Racal just had to come up with 
> a satisfactory replacement.
> Enter the RA1772 which was designed from the floor up with no short cuts.  
> The result was a truly superb receiver.
> Consider at the same time competition was fierce from Marconi, Redifon,  
> Plessey, Rohde & Schwarz, Telefunken etc etc,  remember this was in the  era 
> of "Real" HF CW and voice SSB Communications. WJ did not get a look in, not  
> at least on this side of the "Pond!"
> 
> The thing that sets the RA177X series apart from the others is the very low 
> noise synthesiser with discreet crystal filters, this is basically  superb 
> and the excellent rotary Tuning shaft encoder  is copied right up to the 
> later RA3701 model. Unfortunately the  RA1772 "hang" type agc lets it down - 
> for Amateur use.
> 
> The RA177X series had a useable Preamplifier that would show signals down  
> to -139dBm with a 3Ip of around +35dBm. This was seriously good in 1974, it  
> still is now! Most other receivers of the time, the EK070, E1700, and later 
> E1800 did not have a preamp and consequently had impressive 3Ip figures. 
> But,  under most common circumstances this does not matter at all for us  
> Amateurs.
> 
> The RA1772 was unbelieveably and expensively labour intensive, rather  like 
> the E1500/1700. Even worse for wiring intensity was the RA1784 and  
> RA1778/9 series. So the RA1792 was born, a beancounters dream!
> 
> I think that there is no comparison between a properly aligned (few were)  
> RA1772 and an RA1792. The RA1772 wins hands down BUT from the operational 
> point  of view the RA1792 is absolutely unbeatable!!!
> The later RA1778/9 series is nicer to use than the RA1772 but much  harder 
> to find now.
> 
> For my choice the finest Racal HF Receiver is the Remote Controlled RA1784. 
> These were hugely expensive but had the option of a switchable  600Hz  
> Roofing Filter in them, rather like the RA1772 prototype I was offered many  
> years ago,and, like an idiot, did not purchase! That had a switch, in place of 
> the normal AFC one that switched in an Optional CW Roofing Filter - an 
> Option  that got dropped by Racal as being too expensive at the time, around 
> £600 in  19772.
> 
> If you compare an RA1772 against an RA1792 on the bench the RA1772 wins  
> easily on readability but then, as usual, everything is " Horses for Courses"  
> with the 1792 being much more intuitive to use, but (I believe) it was an  
> American design based on the RA6790GM. For intuitiveness and ease of  
> operation nothing beats American Radios eg. WJ8711A ,  WJ8718, etc etc
> 
> Regards & 73 
> 
> Pat G3YFK
> 
> 
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