[Heathkit] HW-101 Grid Voltage?

[Ed - K9EW]

Hi Howard,

I just had time to Google a 6146 data sheet, and it confirms that - with a
screen voltage of 200v, the grid voltage should be around -50V for a plate
current of 25mA (per tube).  So something is amiss.

A couple of months ago I was struggling with the Plate and Driver tuning
slugs.  I had to replace several of them (cracked), and that seems to be OK
now.  I remember seeing 50mA of plate current without being at the end of
the Bias pot adjustment, so something happened between then and now.

I've already checked the 2.2 ohm cathode resistor, and it's OK.  I checked
the screen voltage, and it's 224V.  The plate voltage is a bit low (658V in
Tune Mode), with fairly high amount of ripple so I'll probably be looking
at the Power Supply next.  I suppose it could also be the 6146's.  I'll see
if I have any more "in stock".  (The PS was already on my list for a
rebuild, but I was hoping I could at least finish the radio first.)

Just when I think I'm about finished, something else pops up.  I guess
that's what comes with a boatanchor.

73,
ed - k9ew

On Fri, Jul 10, 2020 at 9:11 PM Ed - K9EW <k9ew57 at gmail.com> wrote:

> I thought it was on the low side. The manual I have doesn’t have the
> pullout sheets - wha should the screen voltage be? The plate voltage is 658
> volts. Forgot to check screen voltage.
>
> Thanks for your reply, Howard.
>
> 73,
> ed, k9ew
>
> On Fri, Jul 10, 2020 at 8:08 PM howard holden <holden7471 at msn.com> wrote:
>
>> Should be -45 to -55V. Maybe your tubes are low emission? Screen voltage
>> (or plate) way too low?
>>
>> If you happen to have the B version 6146s maybe even -60 or -65V.
>>
>> I have an SB102, similar. Don’t recall the exact reading but it’s in that
>> -50 range.
>>
>> 73, Howie WB2AWQ
>>
>>
>>
>> Sent from my iPhone
>>
>> > On Jul 10, 2020, at 14:28, Ed - K9EW <k9ew57 at gmail.com> wrote:
>> >
>> > What's a typical value of Control Grid Voltage on the 6146's to get the
>> > quiescent plate current of 50mA?  I need to go down to -28V which is
>> almost
>> > the lowest value on the Bias Adjust pot.
>> >
>> > Thanks - ed, k9ew
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