[Boatanchors] 6146 folklore

[Ray Friess]

Gee... i didnt know I'd be opening up such a hornets nest by asking my 
question.  HI HI>
I just wanted to know if maybe I had TOO MANY 6146w tubes in stock (85) 
or if I could use em in my
Apache, DX 100 and dx 40....    also have a dx 60 I'm restoring..
   Ray  wa7itz


Glen Zook wrote:

>And I have seen just the opposite!  Many rigs that
>don't like the 6146B and a relative few that do like
>it!
>
>That is why I say to watch the neutralization (if the
>rig has that capability).  If the rig neutralizes OK,
>and if it holds the neutralization, then certainly go
>ahead and use the "B" and "W" series.  But, if any
>instability happens, then go back to the earlier
>tubes.
>
>In addition, you really should use some type of
>wavemeter (or GDO in the wavemeter position) to search
>for VHF parasitics if you use the "B" series tubes in
>place of the earlier versions.  You might be very
>unpleasantly surprised at the spurious emissions that
>the "B" series is putting out!  Unfortunately, the "B"
>series is much more prone to the generation of
>spurious emissions especially in the VHF range.  Often
>that doesn't really show up readily on the meter
>readings!
>
>Also, although not in amateur service, but in
>commercial service, replacing the 12 volt equivalent
>of the 6146 / 6146A (6883 / 6883A / 8032) with the
>6883B / 8032A / 8552 (12 volt equivalent of the 6146B
>/ 8298A) in the Motorola Motrac series you WILL have
>problems and problems in a hurry in those rigs that
>were not designed for the "B" series tubes.
>
>Again, Collins had to redesign the neutralization
>circuitry in the S-Line and KWM-2 series so that the
>"B" series tubes could be used.  Without the
>modification at least 9 out of 10 units had serious
>problems!  That, I believe, in itself shows the
>problems that can happen with the "B" series!
>
>As I have said before, many amateurs have not had any
>problems using the "B" series in place of the earlier
>versions.  But, many many more amateurs have
>definitely had problems.  As such, I seriously caution
>anyone who uses the "B" series in place of the earlier
>versions to proceed with caution.  If the "B" series
>works properly in their equipment, then that is fine. 
>But, if the "B" series doesn't work properly, then
>they are in for a lot of problems (including damage to
>the equipment) if they persist on using the "B" series
>tubes.
>
>There is no shortage of the earlier versions of the
>6146 family although the "W" versions are sometimes a
>"bit" cheaper and the fact that most of these are the
>"B" equivalent does cause some concern.  However, if
>the purchaser of the "W" types knows what to look for,
>and if they have problems with the "W" types go back
>to the earlier versions, then they will not damage
>their equipment, put out spurious emissions, etc.
>
>However, the problems with using the "B" series tubes
>is NOT an "old wives' tale"!  It is a real situation
>that requires attention to be paid by those who are
>trying to substitute tubes.  Sometimes they work fine.
> But, many times they don't!
>
>Glen, K9STH
>
>
>--- john <johnmb at nc.rr.com> wrote:
>
>I've heard this story about 6146B/Ws over and over,
>yet my first hand experience bears it out only in one
>rig, that being a single HW101.
>
>=====
>Glen, K9STH
>
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>
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>
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