[Amps] TL922A and AL80A

[Steve Katz]

Hi Rich,

It depends on the band and the load, but usually ~50-65W for 550mA Ip.

At that load point, Ep is ~2650V or so, and Po ~950W.  Anode gets orange
after about 30 sec key-down, but tuning to that load point and then
switching to SSB with ~950W PEP seems to keep the tube and the amp very
happy.  Never measured IMD, though.  

Driving the AL-80B with 100W seems to overdrive it regardless of band, i.e.,
no mo' suds, just higher Ig -- so no reason to ever do dat.

-WB2WIK/6

"Success is the ability to go from failure to failure with no loss of
enthusiasm." -Winston Churchill

> -----Original Message-----
> From:	2 [SMTP:2 at vc.net]
> Sent:	Thursday, March 20, 2003 9:45 AM
> To:	Steve Katz;  AMPS
> Subject:	RE: [Amps] TL922A and AL80A
> 
> >
> >
> >
> >> > **  When a single 3-500Z is driven by 100w, IMD is not good.
> >> 
> >> You guys keep arguing about whether a single 3-500z can be run
> >> linearly at 550mA anode current in SSB service. Has anyone
> >> actually measured the difference in IMD for a single tube run
> >> at 400mA and 550mA? Has anyone actually measured the IMD
> >> from an AL-80B at various levels of anode current? I am so
> >> sick of hearing this stupid back and forth pissing contest argument
> >> that I am tempted to go out and buy an AL-80B, the additional
> >> test equipment I would need, and do the test myself :) Talk is
> >> cheap - where is the test data?
> >> 
> >	[Steve Katz]  I surely have no data, but I do have an AL80B on hand
> >and it doesn't require anything close to 100W to drive to Ip >400mA.  In
> >fact, my exciter in its TUNE position, which runs half power (50W CW) in
> >that position, drives the AL80B, properly loaded, to >400mA Ip on all
> bands
> >-- in some cases, to >500mA, after heavily loading it to keep Ig <100mA.
> >Under those condx, efficiency is ~65% and Ep is ~2700V, e.g. 880W RF out
> for
> >1350Wdc.  -WB2WIK/6
> >> 
> **   How many watts of drive is needed to produce 550mA of I-plate/anode?
> 
> 
> -  R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, 
> www.vcnet.com/measures.  
> end