SB401 QUESTION

[Dick Blaney]

Hi Dan,
What you describe sounds normal Heathkit recommended modifications.
Referring to my SB-303 manual, pages 129-131, several modifications are
required to the SB-400/401 to operate transceive with the '303.  I don't
know about the '300 or '301, never had either one of those.  Mods are as
follows per '303 manual:

1. 100 Ohm resistor on front panel Frequency control switch, removed &
discarded.

2.  68 Ohm resistor installed from lug 6 of the switch to the control solder
lug, and another 68 Ohm resistor installed from lug 4 of the switch to the
control solder lug.

3.  Remove the 21 mHz trap coil, (#40-479), from the mixer-bandpass board.

4.  Remove the 270 Ohm resistor and 100 pf capacitor combination and replace
with a 270 Ohm resistor.

Evidently, the previous owner made these mods for an SB-303.  My SB-401 has
had these mods, and works fine.
Hope this helps.
73 de
Dick, WB8MHE
wb8mhe at bright.net

-----Original Message-----
From: Dan Pividal N4VET <OTAKEBI at AOL.COM>
To: HEATH at LISTSERV.TEMPE.GOV <HEATH at LISTSERV.TEMPE.GOV>
Date: Sunday, March 07, 1999 2:35 PM
Subject: SB401 QUESTION


>I have a HeathKit 401 transmitter that I am restoring.
>On the MIXER-BANDPASS BOARD I should have a 21MHz. trap.
>The trap and a related capacitor is missing but the transmitter seems to be
>working fine.
>Does anyone know what the trap was for and why would the previous owner,
who
>is now a "Silent Key", would have removed it.
>Also, if I need to put the trap back in where would I begin to look for it?
My
>manual says it was pre-set at the factory and seems to be a Heath part.
>Looks like it's going to be hard to find.
>Thanks,
>Dan N4VET
>E-MAIL ADDRESS Otakebi at aol.com
>
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