[Premium-Rx] Redifon/SPT RR102 receiver

[John Graham]

Does anyone know of a source of suitable replacement electroluminescent 
backlights for the LCD display of this receiver?  [or others]. They tend to 
have rather a short lifetime, especially when run at a high voltage [240Vac 
in the RR102, with a dedicated transformer winding]. 100-120Vac at a higher 
frequency, eg 400Hz, is more usual.

BTW, I think there was an article about the RR102 in the April 2002 Surplus 
column of the Italian magazine Radio Kit Elettronica. Haven't seen it 
myself, but their other articles on surplus have usually been worth reading.

regards,

John RS86946


> ----------------------------------------------------------------------
> Message: 1
> Date: Thu, 25 Nov 2010 21:51:43 -0000
> From: "Michael O'Beirne" <michaelob666 at ntlworld.com>
> Subject: Re: [Premium-Rx] Redifon RR102 manual for download
> To: <GandalfG8 at aol.com>
> Cc: PREMIUM-RX <premium-rx at mailman.qth.net>
>
> Dear Nigel
>
> 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?
>
> 73s
> Michael
> G8MOB
>
> -----------------------
> 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
>