"Antonio Vernucci" wrote in message
...
I have recently bought a National HRO-5 (octal tubes, rack
mount) with a power supply different from that of another
HRO receiver I have, which is the well-known dog-house
type.

I would like to determine whether the new power supply I
got is original or it comes from somewhere else. It is
absolutely not an home-built supply, but I cannot exclude
that it was modified by someone in some respects.

You may see it on http://www.qsl.net/i0jx/hro-5.jpg It has
a type-80 rectifier, and the socket on the chassis side
has four pins (like the dog-house supply).

Any advice would be greatly welcome.

Also, I would be interested to know where that speaker
comes from.

Thanks and 73

Tony I0JX

Don't know about the power supply but the speaker
appears to be the RCA speaker supplied for the AR-88 or
possibly the AR-77 receivers. If so it should be about 4
ohms impedance and will require a matching transformer to
work with the HRO.
Check the voltages and connections for the PS. It may be
the guts of a rack mounted HRO supply.


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Richard Knoppow
Los Angeles, CA, USA