WHAT AM I DOING WRONG?

[Ed Richards]

Hi Jeff;

Obviously, you are doing something wrong. One tip is to disconnect the
screen resistor from the finals and unsolder the finals plate connection
from the feed-thru on top of the chassis, per the book. The book never
tells you to make these connections until AFTER the alignment. You need
to remove the top and back covers of the PA cage to do this. I have
aligned a number of SB-400/ 401 and never had a problem. Follow the book
faithfully! Do not skip a step or accept a step until it conformers with
the book. TIP: be sure to set the heterodyne oscillator slugs about 80%
of peak on the slow side. TIP: the driver grid coils are a series
arrangement and must be aligned in the order described. TIP: Be certain
to set the driver tuning where it says for each band. Good luck.

Ed Richards

On Tue, 19 Feb 2002 01:00:26 -0700 ejforwood Jerold Forwood
<ejforwood at MSN.COM> writes:
> Hi all,
>
> I need help!
>
> I have 2 SB-401's and I seem to have the same problem with both
> transmitters.
> The first one was working but had low output, only about 40 watts.
> So I started by cleaning all the relay contacts and band switches.
> Then I bought a complete set of new/old stock tubes and started to
> realign the whole thing according to the alignment procedure in the
> manual using my SB-301 connected as a transceiver setup.  I could
> not get more than .2 Volts RF at pin 2 of the 6CL6 driver as I
> adjusted the grid coils.  This was also the same case as I proceeded
> on to the wire between the pins 5 on the 6146A finals and the plate
> coils.  I have the 50ma bias, but I now have no output at all.  I
> have good high voltage, but no grid or plate current.
>
> I bought the second  transmitter an it is a good one.  The LMO dial
> works, even the hairline.  It had about 50 - 60 watts out.  So I
> cleaned and re-tubed and started with the realigning.  This time I
> used the xtal pack as a stand alone.  I have good DC voltage at the
> oscillator test point but low RF voltage from there on.   Now I have
> the same result, NO OUTPUT!
>
> HELP!!!
>
> Thanks and 73's,
>
> Jerry, K0EJF
>
> E. Jerold (Jerry) FORWOOD
>
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