[Kenwood] T-599D Final Amp Tubes

Sat Apr 18 15:59:04 EDT 2009

The original T599 and the early T599A used the S2001's which are
equivalent to the 6146/6146A. The later version T599A and all the "D's"
used S2001A's which are equivalent to the 6146B's. None of the models had
any circuit changes to accommodate the different tubes. In my "D" model
(I've had several over the years and still have one), I've used 6146A's
and 6146B's over the years with no noticeable change in neutralization or
instability all the way up to 10 meters. The original service manual for
the T599A/S/W was later upgraded to include "D" information on the front
cover (now said T-599A/D/S/W) and a loose inserted fly sheet (with
changes to part identification on the front panel). The service manual
schematic never was updated to include the change in final tubes from
S2001 to S2001A. However, the operating manual for the T-599D clearly
identifies on the schematic diagram that the final tubes are S2001A's.

Note, since the plate dissipation is lower on the 6146/6146A's then the
6146B's, your plate input power must be adjusted for less plate current
when using the earlier tubes. Personally, unless you have a trunk full of
6146/6146A's, I would search out of pair of 6146B's or a pair of the
industrial equivalents.

Pete, wa2cwa

On Sat, 18 Apr 2009 17:31:33 +0000 (UTC) w0ng at comcast.net writes:
> 
> 
> Thanks to everybody who responded to my inquiry. 
> 
> Really appreciate the input. 
> 
> 
> 
> My T-599D had S2001 tubes in it when I got it. 
> 
> 
> 
> Joe... what info you cited was indeed the "conflicting" info I ran 
> across. 
> 
> 
> 
> Since one of them is shorted, I'll try a pair of 6146's and see if 
> the neutralization holds. 
> 
> If it doesn't, I'll go to 6146B's. 
> 
> 
> 
> I wonder if the conflicting info published in the Kenwood ops 
> manual vs. the service manual is due to poor translation into 
> English. 
> 
> I ran into this with other Kenwood hybrids in the past. 
> 
> 
> 
> If anyone else out there has more precise info on the issue of 
> whether or not S2001 = 6146 and S2001A = 6146B, please comment. 
> 
> 
> 
> Tnx and 73, Bill, w0ng 
> 
>   
> 
> 
> ----- Original Message ----- 
> From: kenwood-request at mailman.qth.net 
> To: kenwood at mailman.qth.net 
> Sent: Saturday, April 18, 2009 10:00:22 AM GMT -07:00 US/Canada 
> Mountain 
> Subject: Kenwood Digest, Vol 60, Issue 10 
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> Today's Topics: 
> 
>    1. T-599D Final tubes ??? (w0ng at comcast.net) 
>    2. Re: T-599D Final tubes ??? (Peter A Markavage) 
>    3. Re: T-599D Final tubes ??? (Joe LeKostaj) 
> 
> 
> ---------------------------------------------------------------------- 
> 
> 
> Message: 1 
> Date: Fri, 17 Apr 2009 19:39:33 +0000 (UTC) 
> From: w0ng at comcast.net 
> Subject: [Kenwood] T-599D Final tubes ??? 
>  "kenwood at mailman.qth.net" <kenwood at mailman.qth.net> 
> Message-ID: 
>        
<942619408.2757011239997173350.JavaMail.root at sz0147a.emeryville.ca.mail.c
omcast.net> 
> 
>          
> Content-Type: text/plain; charset=utf-8 
> 
> 
> 
> I'd like to ask the group for a little help. 
> I'm finding conflicting printed info on which type of final amp tube 
> should be used in my T-599D transmitter. 
> 
> Is it a pair of 6146B's or the plain 6146's? 
> 
> Tnx, Bill, w0ng 
> 
> 
> 
> ------------------------------ 
> 
> Message: 2 
> Date: Fri, 17 Apr 2009 16:42:48 -0400 
> From: Peter A Markavage <manualman at juno.com> 
> Subject: Re: [Kenwood] T-599D Final tubes ??? 
> To: w0ng at comcast.net 
> Cc: kenwood at mailman.qth.net 
> Message-ID: <20090417.164248.5420.0.manualman at juno.com> 
> Content-Type: text/plain; charset=us-ascii 
> 
> 6146B's for the T-599D. 
> Pete, wa2cwa 
>   
> On Fri, 17 Apr 2009 19:39:33 +0000 (UTC) w0ng at comcast.net writes: 
> > 
> > 
> > I'd like to ask the group for a little help. 
> > I'm finding conflicting printed info on which type of final amp 
> tube 
> > should be used in my T-599D transmitter. 
> > 
> > Is it a pair of 6146B's or the plain 6146's? 
> > 
> > Tnx, Bill, w0ng 
> 
> 
> ------------------------------ 
> 
> Message: 3 
> Date: Sat, 18 Apr 2009 09:59:31 -0500 
> From: Joe LeKostaj <k9ly at comcast.net> 
> Subject: Re: [Kenwood] T-599D Final tubes ??? 
> To: "kenwood at mailman.qth.net" <kenwood at mailman.qth.net> 
> Message-ID: <p06240801c60f9790eaa3@[192.168.0.3]> 
> Content-Type: text/plain; charset="us-ascii" ; format="flowed" 
> 
> Bill, 
> 
> My T-599D operating manual says "S2001 (6146B)" on the Features 
> page, 
> but I believe this is an error. Is this the conflicting info you 
> mentioned? My understanding is that S2001 = 6146/6146A, while S2001A 
> 
> = 6146B. 
> 
> Everywhere else in the T-599D manual it calls the finals S2001, and 
> that is what my T-599D contains. So I would replace them with 
> 6146/6146A, not B. 
> 
> The service manual for TS-530S says it uses "S2001A/6146B". So 
> evidently Kenwood switched to the B version for their later tube PA 
> models. 
> 
> HTH. 73, 
> Joe K9LY 