[Elecraft] [k3] Tone/"Low Bat" indication?

[S Sacco]

Dave -

About 5 minutes after I hit [SEND] on that last e-mail, I remembered that
I'm not using the supplied DC cable, but instead have a rather long DC cable
running to the K3; I'm sure that's where the loss is coming from.   I'll
look into shortening it.

I also soldered the PP connections.

I've left my DM-330MV set to the default 13.8 v, but raising it is certainly
easily doable.


Thanks again & 73,

Steve
NN4X

On Sun, Apr 5, 2009 at 12:08 AM, David Gilbert <xdavid at cis-broadband.com>wrote:

>
> Glad that helped,  Steve.
>
> You might want to continue your troubleshooting, though.  I use exactly the
> same Alinco DM-330MV power supply with the same stock Power Pole connectors
> that came with the K3, and while I have considered shortening the power
> cable that Elecraft provides I have not yet done so.  I normally have my
> DM-330MV set for 14.5 volts per the earlier discussions here on the
> reflector about SSB linearity, but I temporarily adjusted the voltage back
> down to 13.6 volts in receive to match your conditions.  With the K3 set to
> 95 watts, I show 13.0 volts in transmit.  At 45 watts, I'm holding 13.3
> volts.
>
> I'm not sure what the difference might be, but we're getting significantly
> different results from the same power supply.  For what it might be worth, I
> carefully soldered the connections between the cable and the Power Pole
> connectors when I assembled it.
>
> 73,
> Dave   AB7E
>
>
>
>
> S Sacco wrote:
>
> Hi Dave -
>
> OK, sorry for the misunderstanding; I thought you were talking about the
> K3's internal battery.
>
> Now that we have that out of the way:
>
> 1) "BAT MIN" is set to 11.0 v
>
> 2) When I measured the voltage using the K3's internal metering:
>     a) It was 13.6 v at receive
>     b) It was 10.8 v while transmitting 95 watts output  **** Clearly, 10.8
> < "BAT MIN" ****
>
> 3) I measured disconnected and reconnected the Anderson Power Pole
> connector at the back of the K3, and the voltage increased to 10.9.
>
> 4) I have the power from the power supply (an Alinco DM-330MV) running to a
> set of fuses before continuing on to the K3.   It's one of those gold-plated
> dressy looking deals that car audio folks use to bling-out their
> installation (I got them cheap at Skycraft Surplus here in Orlando about 10
> years ago).
>    a) I removed both fuses (one for +, one for - ) and treated both the
> fuse and the holder with DeoxIT.
>    b) At the same time, I treated the PowerPole with DeoxIT.
>    c) I also noted the the - lug on the back of the Alinco was slightly
> loose, so I tightened it.
>    d) My apologies for not doing one thing at a time, and then measuring
> the result; that would have been the proper procedure.
>    e) Upon the above treatment and actions:
>         i) The voltage rose to 13.7 v at receive
>         ii) The voltage rose to 11.4 v while transmitting 95 watts
>         iii) To add another datapoint, I reduced the power to 45 watts
> (typical power when driving my amp) and the voltage was 12.0 v.
>
> Conclusion: Voltage drop due to I squared R losses.
>
> I didn't measure the voltage on both side of the fuses before the DeoxIT
> treatment, which was another mistake in my diagnostic approach.  I did so
> after the treatment, and noted a voltage drop of only .1 volt (from 12.9 to
> 12.8) across the fuses while under load.
>
> Thanks for the tip Dave; it was much appreciated!
>
> I've Cced the reflector, and hope this serves as a good example for
> everyone to mind their connections.
>
> 73,
> Steve
> NN4X
>
>
>