I've gone to Surplus Sales' website. I don't see physical dimensions for
the various mica/ceramic caps posted there.
1) Are there archives of old Ten-Tec newsgroup postings that I can search
through for details on what components others have ordered.
2) Is there anyone who can privately e-mail me the list of caps that they
ordered from Surplus Sales for their Titan..ie. part #'s etc.
3) Any "gotchas" I need to look out for when I'm ripping out the loading
caps? Any suggestions?
Thanks
Tom K2TA
tom@k2ta.com
----- Original Message -----
From: "Tom A" <althofft@concentric.net>
To: <tentec@contesting.com>
Sent: Monday, March 17, 2003 8:28 AM
Subject: Re: [TenTec] Omni VI & Titan tuning repeatability
> Without a doubt tuning drift is caused by the fixed caps in the loading
> circuit and not by the .001 blocking caps.
>
> Was this a bad brand of caps? Bad design (too low current / voltage
> ratings)? Aging of components?
>
> If I have to get into cutting out a bad cap I'm going to go through the
> trouble of replacing all the fixed caps with higher ratings..including the
> DC blocking caps. I'm beginning to not trust any of the components in my
> Titan. It's turning into a ground up re-build. But it will be a
> better-than-new amp once I'm finished.
>
> Anyone taking odds that now that I've replaced every cap in the PS, new
> meter bulbs, tightened and lubricated band switch wafers, replaced all the
> loading caps....
>
> That the first time I hit the key the tubes will head off into the sunset?
>
> Tom K2TA
> tom@k2ta.com
>
>
> ----- Original Message -----
> From: "Dr. Gerald N. Johnson, electrical engineer" <geraldj@isunet.net>
> To: <tentec@contesting.com>
> Sent: Sunday, March 16, 2003 8:30 PM
> Subject: Re: [TenTec] Omni VI & Titan tuning repeatability
>
>
> > The plate blocking capacitors should be the least effect at 160 meters
> > because the tube plate C is far less than the tuning C. At 10 meters the
> > tube plate C is a large fraction of the circuit tuning C so changes in
> > the blocking capacitors may have a greater effect. On the other hand the
> > tube C is maybe 20 or 30 PF and the 1000 pf series C of the blocking
> > capacitors can change a lot without changing the effective tuning C. But
> > the posted complaint was loss of output at 160 meters, not 10 meters.
> >
> > On the other hand, loading padding capacitors are only in the circuit on
> > the low bands and drift in their value will change the output of the
> > amplifier.
> >
> > Only changing 45% seems small for the Z5U dielectric. I've seen some
> > loose 80% from room to soldering temperature. Suitable only for
> > uncritical bypass applications when the bypass capacitor has been
> > selected to have several times the value needed for stability. NOT
> > suitable for any kind of tuned circuit.
> >
> > 858s are good, expensive, and hard to find, but good for RF circuits.
> >
> > 73, Jerry, K0CQ
> >
> > --
> > Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
> > Reproduction by permission only.
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
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