Tube breadboard

[Bill Layer]

Hi All,

I'm working to document it at home. It'll take me a while before my anal
retentive attributes are satisfied, so please be patient.

As a preview, the system is based on octal relay sockets, the type with the
screw terminals disposed about the base of the relay. Salvaged (hollow)
octal tube bases are fitted with various tube sockets and made into
"adapters" to allow any base to be plugged into the board via the common
octal-base.

Since octals are some of the best and most plentiful audio tube, they are
supported directly via the sockets; no adapters needed. Since the pinouts
of the relay sockets are un-dedicated, it's easy to see how any type of
hookup is possible.

The passive components are mounted on terminal strips which are placed
between the sockets as required. It's possible to mount the passive
components with Fahnestock clips to make this a 'solderless' breadboard,
but I'd recommend just solder-tacking them for your sanity...

Finally, a power supply must be selected. I would suggest a surplus unit,
that you carefully rebuild, as constructing a unit of equivalent quality
would be very expensive. If at all possible, get a regulated supply... I
have a Lambda model 71 built in Long Island City, in 1951. It was $798 back
then, and the quality of this unit is beyond reproach. Heavily overbuilt
doesn't even begin to describe it. Specs: +/- .1% load and line. 0-500VDC
at 200MA, 6.3VAC x 2 at 7A. It uses about 18 tubes, all of which are
readily available, and cheap. Cheap except for the 5V4GB main rectifier, at
about $25.00.

However, the supply could be as cheap as a 110-240V step up driven from a
variac, and hooked up to a simple RC filter. That would give you 330 VDC
with the vario wide open. Use a cheap 6.3V AC xfmr to run the heaters.

Sound good so far?

  
Bill Layer
Sales Technician
<b.layer at vikingelectronics.com>

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