[Premium-Rx] Redifon RR102 manual for download

[GandalfG8 at aol.com]

In a message dated 25/11/2010 21:51:53 GMT Standard Time,  
michaelob666 at ntlworld.com writes:

Many  thanks for the link to the manual.  I did see one of these receivers 
at  
a rally two years back but passed it by as being not really a PR type  
radio. 
But I must say the circuit seems to be very competent and it  appears to 
use 
a proper quatrature detector for AM.

The real  manufacturer is clearly SPT, and judging by the typewritten 
manual, 
must  be quite a small outfit.

Have you any experience of this  rig?
-----------------------
Hi Michael
 
Yes, you're quite right, it was an SPT product.
Although the manual is just marked SPT I'm not sure if they  were already 
part of the Redifon/Redifussion group at that time but  the label on the set 
refers to them as Redifon SPT Ltd so the set is often  referred to as a 
Redifon product.
 
SPT in this instance stands for "Sound Powered Telephones", which I think  
is a lovely name for a radio/electronics company, makes me feel that we 
should  really refer to the RR102 as a "wireless" rather than a radio:-)
I don't know if SPT still exist but as of April 2000 the RR102 was  still 
listed in the MOD Def Standard 02-571, Guide to Sound Reproduction  Equipment.
 
I have got one, not used it much but might do if I ever have find  enough 
spare space near where I'm working:-)
As a broadcast receiver I think it's been a fairly well kept secret, a  few 
years ago they were selling for up to £100 each but as more were released  
average Ebay prices seemed to drop to around £40 to £50 and I've seen them  
go for under £20.
 
As it stands it is very strictly broadcast use only, no SSB or CW  option 
and display resolution only 1KHz, but for it's intended purpose I'd much  
prefer one of these to the much over hyped, and usually well over  priced, Lowe 
HF150 any day.
I did consider modifying it for SSB/CW, just for the sake of giving the  
HF150 even more of a run for its money:-), but have more radios than time  so 
haven't pursued that.
 
Two mild downsides, no internal amp or speaker as it was intended to be  
mounted in an audio distribution console, and a pair of protruding Belling Lee 
 TV type connectors for the separate AM and FM antenna inputs that I'll 
probably  replace with BNCs if I do keep it.
 
Design wise it certainly follows more professional techniques than the Lowe 
 series, non of this LO adjustment by pulling the winding about on a toroid 
and  hoping it stays stable for example, a couple of SBL1 mixers in the HF  
section as another example, and a block of 10 bandpass filters at the HF 
front  end. 
 
The bandpass front end filters are probably a bit of overkill  for those of 
us not using it at sea next to some hefty  transmitting gear, but nice to 
have all the same:-)
 
A recent Ebay auction, 170566261971, and still  viewable at time of writing 
has a couple of nice internal photos, although that  single RF PCB, which 
mounts on the hinged top cover is normally  covered by a screening plate.
 
regards
 
Nigel
GM8PZR