[Hallicrafters] Voltage question re SX-71

[Lee Bahr]

Bob:
Part of the problem is:  line voltages are higher today then when the manual
was published. Back then line voltage was around 110 to 115 volts.  Today,
voltages are running around 120 volts or even slightly higher.  Lower your
line voltage with a variac and I bet things will look a lot better.
Lee, w0vt



> Good morning to all
>
> Back with another SX-71 question. I posted a few weeks back about
re-capping
> and re-sistoring my ebay SX-71. The radio sounds very hot on the HF bands
> and i am very pleased with it. FWIW, i decided to check the tube voltages
in
> the IF strip against the TUBE SOCKET VOLTAGE CHART in the manual. Big
> mistake :(  I found that the voltages in my radio are nowhere near those
in
> the chart. The anode and screen voltages on IF2 and IF3 are 20-30 volts
too
> high, and the cathode voltages are either way high or way low.
> I have all the front panel control settings as indicated in the chart, the
> B+ and regulated voltages are correct (250V and 150v resp'ly). All
resistors
> are new 1% xicons, and their values match those in the circuit diagram,
and
> they test correct. The tubes are NOS and tested ( i have one of those
bright
> red Hickocks :) and i have tried several in each IF socket.
>
> Here's my question... were Halli radios made with such wide tolerances
that
> a 20-30 volt difference is acceptable?
>
> By way of comparison, i also recapped and re-sistored an ebay NC183D
during
> the same period. It's voltages are all within a few volts of its chart.
>
> thanks in advance for any help
>
> Bob Bennett, Maple Vly, WA
>