[Boatanchors] Mercury Rectifiers

[Jim]

I miss the pulsing blue glow of 866's in a darkened room.
The slight buzz served as a side-tone.....
The radio seemed to breath and be alive..........

Alas, solid state rectifiers are more efficient and don't "flash back"

but I miss the pulsing blue glow....

Jim

>
>
> Of course, the other "fix" is to replace the 866 tubes with 3B28 types.
> No mercury vapor problems, no long preheat required, etc.  3B28 tubes
> are Xenon filled, and don't glow nearly as much as 866s do (they do
> glow, just faintly), but they are a whole lot more forgiving.  And, if a
> bit of heresy may be permitted,  a couple of diode stacks from otherwise
> defunct microwave ovens will make a tidy replacement, give a bit more
> B+, save some cabinet heat, and some electricity (no filament
> transformer), and are "instant on".  I guess it depends on whether a
> person cares how something looks, or how it works.    Each to his or her
> own.   I replaced the 866 tubes in my old Heathkit "Warrior" amplifier
> (4 X 811A), first  with 3B28s and then later with diode stacks - and
> never looked back.
>
>
> - Jim, KL7CC
>
>
>
> Nick England wrote:
>> I sent John a copy of the relevant pages in the RCA Transmitting Tubes
>> manual TT-4 which has a very good discussion of the topic. RCA says
>> Preheat and Condition.
>> Summary -
>> Preheat with normal filament voltage at least 30 minutes with no anode 
>> voltage.
>> Let cool and condense.
>> Then Condition at normal filament voltage and apply 1/6 normal anode
>> voltage (after the usual mandatory recommended warm-up period) for 5
>> minutes. Gradually increase the anode voltage over 30 minutes. If a
>> flashover occurs during this process, reduce anode voltage until
>> flashover ceases, maintain this reduced voltage for a few minutes,
>> then resume the treatment.
>>
>> http://www.we0h.us/Amateur_Radio_stuff/Books/RCA-TT-4-Transmitting-Tube-Manual.pdf
>>
>> cheers,
>> Nick K4NYW
>>
>> On Mon, Apr 23, 2012 at 11:31 AM, J. Forster <jfor at quikus.com> wrote:
>>
>>> Hi,
>>>
>>> Is there an issue with Mercury pooling in rectifiers, like the 866, in
>>> long term storage that would cause them to blow over more easily?
>>>
>>> If so, is there a fix?
>>>
>>> Best,
>>>
>>> -John
>>>
>>>
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