[Heathkit] Two Question about SB430 Tune Mode

Sat, 26 Jul 2003 23:06:24 -0400

Well,
First of all, from my experiences with the SB-sets I have several combos
of
SB-401/SB-301 SB401/SB-303 rigs used for various modes. While
refurbishing them and repairing them I found that the crystal holders
were suffering from
fatigue. The sockets are migrating away from the pins on the crystals.
In the transmitter the problem is exacerbated by the fact that the TR
relay is in close proximity to the crystals causing extra vibrations.
The reason you can
get power output by rapping on the transmitter is explained there. Or
course
DON'T overlook a bad crystal from time to time.

As for the usage with the receiver, there is no tune position on them,
the
receiver mode switch MUST be in the CW position if you want to tune the
transmitter. Simple as that. Also make sure the LMO load is in for
stand-alone and patched with 90 ohm coax NOT RG-58/(*). Drive levels
suffer
with the wrong cable installed.

Hope this helps. Rigs at this QTH can be seen at:
http://eshop1.chem.buffalo.edu 

Jim
WB2FCN

[email protected] wrote:
> 
> I have two question about My SB 303 and SB401 combo.
> Since I got the station I thought I had a problem with the transmitter.
> When I go to the tune mode I sometimes get no RF output.
> After a couple of cliks of the tune control I get output.
> I cleaned the control and soldered boards and looked for bad connections to no avail.
> Then, I noticed that if I tapped near the three xtals under the rig I would get full output.
> If I tapped again it would fall to 0.
> If I turn the transmitter on and speak into the mike my O'scope shows full output and no drop.
> Now, here are the two question and, maybe the answer will help others having the same problem so please post answers on the reflector.
> When I tune the transmitter locked to the SB 303 and place the SB 303 mode switch on CW also I can go to tune on the mode switch of the SB 401 and it works perfect.
> Does the SB 401 have to be in CW mode to tune the SB 401?
> Could I have a bad CW Xtal on the SB 401?
> The manual says that both units have to be in the same mode
> Since no tune position exists on the SB 303 I have always thought that I could leave it on USB or LSB to tune the SB 401.
> Oh yes, always one more question.
> If you all think I have a bad CW Xtal on the SB 401 where can I buy one of those bad boys.
> Would anyone on the reflector have one for sale that works and would be willing to sell?
> That is it.
> Thanks,
> Dan N4VET
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