[time-nuts] HP 5370A to B conversion

2014-12-18 Thread Perry Sandeen via time-nuts
List, I won a 5370A from ebay. Though it seems to be missing the A channel level knob, the unit was shown powered up with the correct 0.0 on the display, although the unit was sold as non-working for parts or repair.  But the price was right with a best offer accepted. So assuming (gulp) that th

[time-nuts] HP 5370A to B conversion

2014-12-19 Thread Mark Sims
It's not practical to convert an "A" to a true "B" model. They use a different input front end circuit. But, the rest of the machine is compatible. The "B" firmware runs on a "A". John's CPU board works on either version. _

Re: [time-nuts] HP 5370A to B conversion

2014-12-19 Thread Chuck Harris
There really is no need to convert it to a B unit, as the A unit has the same specifications. If you put John Seamons' BBB CPU card in it, it will simply sing as far as speed goes, and you can use the A or B virtual roms as you wish. The principle difference is the B analog boards are easier to

Re: [time-nuts] HP 5370A to B conversion

2014-12-19 Thread Poul-Henning Kamp
In message , Mark Sims writes: >It's not practical to convert an "A" to a true "B" model. They >use a different input front end circuit. But, the rest of the >machine is compatible. The "B" firmware runs on a "A". John's CPU >board works on either version. The only differene in the

Re: [time-nuts] HP 5370A to B conversion

2014-12-19 Thread Dan Rae
I saved a bunch of 5370A boards from being sent for gold scrap at a recent TRW swap meet. A lot of the boards are common to both A and B versions. If anyone has a need for any particular board, let me know off list please. Nothing from the front panel. Dan __

Re: [time-nuts] HP 5370A to B conversion

2014-12-19 Thread Magnus Danielson
There is a mod on the A model which was fixed in the B version. As I recall, it was to reduce cross-talk. Bruce the almighty might recall better than me. I would recommend Perry to apply the BBB based CPU-boards. Good use of the hardware at hand. Cheers, Magnus On 12/19/2014 02:55 PM, Chuc