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Author Topic: Questions on tuning an 811H with a 3898 Pecker.  (Read 12815 times)
W8JI
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« Reply #15 on: January 11, 2012, 07:45:17 AM »

Tom,  Not pushing for info before it's released, but we're all very interested in what this new tuning aid is, and how it works.

Any idea of time frame before you're ready to release some info - maybe a product on market?

73 de Ken H>

Don't know, but I need to finish testing.  :-)
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VE7RF
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Posts: 212




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« Reply #16 on: January 11, 2012, 11:39:59 PM »

Just don't see the need for it.  I MAY have abused my amp the first time I determined the appropriate settings, but after that it's just set to the pre-established settings, tweak a teeny bit, and that's it.

Doesn't seem to justify buying another device.

##  tuning pulsers  have been around since the mid 70's.....nothing new here. They work great imo.   Why beat the crap out of your linear using a dead cxr, when you can just pulse tune the amp.  On my yaesu  MK-V, you can lengthen or shorten the dots..in the menu.  By using that, I can shorten the duty cycle from 20-50%.   Then just crank up the built in keyer to 60 wpm.   Use a peak reading wattmeter..and you are laughing.  If the amp is rated for say..1.5 kw pep...then just pulse tune it  for 1.5 or 1.6 kw pep... and ur done, it's that simple.   OK, THEN hit it with a 2 sec dead cxr... just long enough to get some steady state grid + plate current readings. Switch to ssb mode..and tweak the PO on the xcvr, if required, so u have 1.5 kw pep [ or what ever ur amp runs at].

## My problem with the  3980 pecker is it's an audio type pecker. It also has NO output level control, and the output is usually way to high on it. It really needs   a simple pot on the output, to drop the level down a bit, so you don't have the ALC on the xcvr  blown off scale.

##  SOME xcvr's will have slightly higher po on ssb  vs  cw  for a given PO setting on the xcvr..and some are vice versa.   A lot of linears are NOT rated for CCS cxr output, and will cook the xfmr/tubes etc, if tuned with a dead cxr.  The other thing when tuning with a cxr is... what if the tune control is way off resonance?  Now you have way too much plate current, PO out of the linear is way down..and anode diss is sky high.  IMO, if ur gonna have it slightly off resonance, then at least do it while pulse tuning.

##  The array solutions power master peak reading wattmeter  makes pulse tuning a snap. It has an 80 segment bar graph +numerical readout. The bar graph is also auto ranging.

##  Once the amp in question is tuned up on each band, then write down the tune + load numbers, so at least you can  pre-set the amp and be 95% in the ballpark.  Then pulse tune for the final tweak.

Later... Jim  VE7RF
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