[ARC5] SKN -- Post Mortem

Thu Jan 2 19:18:12 EST 2014

Evening Lads --

As I suspected, the Ip meter was the culprit.  It was reading 70 to 80 mA
too high.

I tested with 2 additional meters, and the 2 agreed so I just replaced my
Ip meter.

40M:  Ep 540  Ip 150  Pout 40W

80M:  Ep 534  Ip 168  Pout 30W

Power output on 40M is just about what I'd expect, perhaps a tad low.

The Power output on 80M is low, but it may be the tubes.

Don't know why I told you guys my Ip was 300 mA last night (maybe too much
SKN?);  the bad meter was indicating 240 mA.

73 Mark K3MSB

On Wed, Jan 1, 2014 at 10:21 PM, Mark K3MSB <mark.k3msb at gmail.com> wrote:

> Hi Dennis
>
> I'm not so sure upon further thought.   The only problem I had with my 40
> and 80M transmitters was that the tone on the 40M unit was ugly last
> September.   Other than that, the Ip was slightly less than 200 mA for an
> Ep of 525 or so on BOTH units.   I can't remember the power output but it
> was between 30 and 40 watts for each transmitter.
>
> So, what changed, since this is happening to both transmitters?    I
> replaced a zorched external Ip Meter and modified my PS by adding a simple
> disc ceramic bypass capacitor, and added grounds.
>
> I did check the "new" old Ip meter and it looked good, but I'm
> wondering.   I think over the weekend I'll add another meter in the plate
> line and see what it says.
>
> Mark K3MSB
>
>
> On Wed, Jan 1, 2014 at 9:51 PM, Dennis Monticelli <
> dennis.monticelli at gmail.com> wrote:
>
>> Mark,
>>
>> Only 20W for 165W input?  Those 1625's are really heating up your shack.
>>  I'm surprised they don't show plate color.  I'm getting 30W out for 500V
>> at 100mA.  60% efficiency is about what you can expect at those plate
>> voltages with 807 types.  Something is way out of whack in your final
>> network, but I'm sure you'll track it down and fix it.
>>
>> Tim,
>>
>> Thanks for coming back to my CQ.  I tuned around and found your rockbound
>> signal on 7050 along with about three others :-)   Nothing wrong with your
>> sig strength, though.
>>
>> Dennis AE6C
>>
>>
>>
>>
>> On Wed, Jan 1, 2014 at 4:23 PM, Mark K3MSB <mark.k3msb at gmail.com> wrote:
>>
>>> Well I made 5 more QSOs late this afternoon on 40M, but wasn't able to
>>> contact any of the denizens in this thread (which I renamed.....)
>>>
>>> Overall I was pleased with the performance of the SCR-274N.  The issues I
>>> saw were
>>> 1) Slight drift on 40M.   Not bad at all once the radio warms up.
>>>
>>> 2) I'm only getting 20W or so of output on 80M with 550V Ep and 300 mA
>>> Ip.
>>> I'm using a 200 pF series capacitor and that may be to much.  I want to
>>> build the "tuner" circuit in ER (the one with the 200 pF series cap into
>>> a
>>> parallel LC tapped network.   My output on 40M with a different series
>>> cap
>>> is 40W with 550 and 300.
>>>
>>> 3) I notice that my antenna coupling control is always at max for max
>>> power
>>> regardless of the inductor setting;  I'm not sure what to make of that.
>>>
>>> 4) Selectivity.  Thanks for the comments about getting an audio filter.
>>>  I
>>> will check into that.
>>>
>>> As I said, I had a great time in the SKN.
>>>
>>> Plans, Lord willing, for 2014:
>>>
>>> Address the above SCR-274N concerns
>>> Get the BC-456 modulator in the system
>>> Beat the bushes for the trays/racks I need for the 274N.
>>> Start restoration on my BC652.BC653 Tank Radios
>>>
>>> Happy New Year to y'all.
>>>
>>> 73 Mark K3MSB
>>>
>>> On Wed, Jan 1, 2014 at 5:49 PM, Tim <timsamm at gmail.com> wrote:
>>>
>>> > Hi Ken - good signals!  Seems to still be a lot of SKN activity out
>>> here at
>>> > 2230Z but the band is still fairly short - you are the longest range
>>> QSO
>>> > for me today....
>>> >
>>> > QSL "in the mail" !
>>> > 73 & HNY
>>> > Tim
>>> > N6CC
>>> >
>>> >
>>> > On Wed, Jan 1, 2014 at 1:18 PM, Kenneth G. Gordon
>>> > <kgordon2006 at frontier.com>wrote:
>>> >
>>> > > On 1 Jan 2014 at 12:56, Tim wrote:
>>> > >
>>> > > > Hi Ken - I am QRV on 7050 Kc if you need yet another Kalifornia
>>> > > > contact! GRC-109 73, Tim N6CC
>>> > >
>>> > > I would like to work your 109 anytime, Tim.
>>> > >
>>> > > We just got finished with our Holyday prayers, and I'll run right
>>> down to
>>> > > the
>>> > > shack.
>>> > >
>>> > > Kenneth G. Gordon W7EKB
>>> > >
>>> > > "Courage is being scared to death but saddling up anyway."--- John
>>> > > Wayne
>>> > >
>>> > >
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>>
>>
>