This is a page about Betamax and some technical information

I own a number of Betamax VCRs, my favourite is my Sony SL-HF950

My others are a Sanyo VTC-M40, Sony SL-F1UB portable, and a Sony SL-HF100P.

I did own a Sanyo VTC6500 but sold it as it took up too much room and I have all 3 HiFi decks

Some good links
Betamax PAL Site
How I got a 950
LANC Protocol - Interesting - found it ages ago - applies to 950
Colins Beta Page

The Sony SLHF 950 must be the video recorder most worthy of being converted to NICAM.
Parts required:
AVTS NICAM decoder  
AVTS Parallel IF board  
Box for decoder 
Power supply if not using 950 power +12v 
2ft ribbon cable 4 wires  
Thin coaxial cable 
Phone Plugs & Sockets Minimum of 4 each Maximum of 14 each
0.1" PlugsUse to replace interboard lead
The Parallel IF board is necessary because the 950 SAWF will not pass the NICAM sub carrier - this took me nearly a year to sort out.
Now dismantle your 950 - a workshop manual is very useful! The top comes off first, then carefully unscrew the back panel and remove, now drill 4 holes in it to fit the phono sockets as per picture, if you are using 950 power you will need lines for +12v +5v and 0v (earth), a stereo sensor line is also required. These 4 lines can use a DIN or other small socket (even wires put through grills! - I did this for stereo).
Now refit the back (with sockets fitted) and remove the bottom of the 950, unscrew and hinge out of the way the bottom circuit board - it's easier than it seems as the 950 is a very well built video recorder. The easiest way to do the next job is balancing the 950 on either the front or the side at the cassette end, make sure it is on a padded surface. The two boards we need to access are the top board TA37 and the third board AF14. Make up the interboard cable as shown and fit it plugging into connector CN002 on TA37 and connector CN012 on AF14. Reassemble the bottom of the 950 but leave the lid off.
Join the two coaxial cables coming from TA37 together and solder to the FM out socket. Connect the cables from AF14 via the small circuit to the Stereo In sockets.
Unscrew and hinge up the TA37 board and connect the IF out socket to the circuit board where shown. Cut the tracks joining IC009 pins 23 & 24 to a resistor and solder a cable from the pins to the stereo sensor socket. This is all the audio circuit modifications required by the video.
Power supply, external. A small 12v transformer is required, just fit in the box with the decoder and parallel IF board and connect up. This is what I did as I was given a transformer and started the conversion before I got the 950 manual.
Internal, connect to psu board ect. I may convert mine to this system in the future.
Decoder box. Fitting sockets to the box is both safer and tidier than connecting the 950 to decoder cables direct to the board. Connect the stereo out lead to the stereo sockets, the FM cable to the FM in socket and the IF in cable from the board to the parallel IF board as shown, connect the IF in socket to the parallel board also. Connect up the three power leads, +12v & +8v on the main board, +12v on the parallel board, the 2 earths, connect the sensor cable to the second hole down as shown.
Now connect to the 950 and switch on. If the board LED (if fitted) or the 950 stereo indicator light up congratulations, otherwise it is likely that the variable inductor on the parallel IF board needs adjusting. As the new boards 'burn in' it is likely that the inductor will need readjusting.
Now switch the TV to line or connect the 950 to the hifi and enjoy the stereo!
This conversion is easier than it seems and is capable by any one with a little electrical experience. It took me hours of following signal paths inside the deck to work out where to get the FM from, where to put the stereo back in, and worst of the lot how to operate the 950 stereo indicator.
If any problems are encountered the 950 can be operated with the board disconnected by connecting a phono plug to two phono plug lead between FM out and stereo in.