[Boatanchors] NEED TUBE INFO

[EP Swynar]

Hi Guys,

I don't know where the notion came up that just because a rig uses 2.5
filament tubes then, by default, the rectifier tube has to be 2.5 volts as
well...!

Nothing is further from the truth...and I hate to tell the non-believers
reading this, but an 80 is just like a 280, performance & specs-wise --- the
sole difference *could* be in the glass envelope used by each, i.e. the
older 280-type uses a globe / balloon envelope, whereas the 80 (or, in the
shortened form it became known as, the '80) has a shoulder-type envelope...

Check any of the older issues of QST: you'll see power supplies illustrated
therein using the abbreviated '80 designator (short for 280), hooked-up to a
5.0 VAC filament winding of the power transformer.

I've interchanged 280 tubes with 80 tubes in my HB projects here, and have
NEVER "flamed-out" the filament of ANY supposed 2.5 volt 280 by treating it
like an 80, with 5 vac on the filament...that SHOULD have happened if there
was a difference between the two types, and in very short order, too. But it
never has, never will...

Perhaps somebody here has 80 / 280 tubes confused with the mercury vapoured
'83 tube...? Now, it --- or some other designation --- share the same
characteristics, EXCEPT for the filament voltages, i.e. 2.5 vac versus 5.0
vac...

~73!~ Eddy VE3CUI - VE3XZ

***********************

----- Original Message ----- 
From: "Brian Goldsmith" <brian.goldsmith at echo1.com.au>
To: "'BOATANCHORS'" <boatanchors at mailman.qth.net>
Sent: Saturday, July 21, 2007 5:12 AM
Subject: [Boatanchors] NEED TUBE INFO


>
>
> -----Original Message-----
> From: David Hollander
>
>
> Brian - once again, the 280 rectifier is a 2.5 volt filament tube. It is
> the2.5 volt version of the 80 rectifier. The National 5887 doghouse supply
> uses one to power the FB-7 receiver 2.5 volt tube version. The National
5880
> doghouse which is for the 2.5 volt version of the SW-3 also has a 280 in
the
> power supply. The doghouse supplies for the early national receivers using
6
> volt tubes uses an 80 rectifier.
>
>
> ***** The following people from the Tube Collectors Association do not
agree
> with you and present some data sheets to back them up.I agree with you
about
> the 280A.
>
> >>1) Re: 280 Rectifier
>     Posted by: "Donald Daykin" daykin at ameritech.net drdaykin
>     Date: Fri Jul 20, 2007 6:54 am ((PDT))
>
> Believe me, the 280 has a 5-volt filament. Since they need separate
> windings, it makes no difference what the voltage is for the other tubes.
>
> Donald
>
> >>2) 2c. Re: 280 Rectifier
>     Posted by: "Roger P. Walker" rp.walker at btconnect.com rp.walker
>     Date: Fri Jul 20, 2007 7:23 am ((PDT))
>
> The 280A is a MV rectifier with a heater of 2.5V 3A but 280 seems to be 5V
>
>
> >>3) From: tubecollectorsassociation at yahoogroups.com
> [mailto:tubecollectorsassociation at yahoogroups.com] On Behalf Of Donald
> Daykin
> Sent: 20 July 2007 14:54
> To: tubecollectorsassociation at yahoogroups.com
> Subject: Re: [TCA] 280 Rectifier
>
> Believe me, the 280 has a 5-volt filament. Since they need separate
> windings, it makes no difference what the voltage is for the other tubes.
>
> >>4) 2d. Re: 280 Rectifier
>     Posted by: "Tony" tonydaggs at comcast.net bone433
>     Date: Fri Jul 20, 2007 5:36 pm ((PDT))
>
>
> http://www.nj7p.org/Tube4.php?tube=280
>
> Tony
>
>
>
> Brian Goldsmith.
>
>
> _______________________________________________
> Boatanchors mailing list
> Boatanchors at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/boatanchors
> ** List Administrator - Duane Fischer, W8DBF/W9WZE **
> ** For Assistance: dfischer at usol.com **
> $$ For vintage radio info, see the HCI web site $$
> http://www.w9wze.org