SB-313 Receiver Problems

[Joe]

Common problem, you have a poor ground path (oxidation) on the tuning cap
shaft contacts.
Clean up the 2 rotor shaft contacts.
You can also improve the path by adding some braid from the shaft stop
points to gnd.
-----Original Message-----
From: Jim Bo <jbollit at IX.NETCOM.COM>
To: HEATH at LISTSERV.TEMPE.GOV <HEATH at LISTSERV.TEMPE.GOV>
Date: Monday, September 06, 1999 8:13 PM
Subject: SB-313 Receiver Problems


>I have an SB-313 with a problem and I am hoping someone here can
>help me.
>
>The radio receives short-wave stations, but the tuning seems
>"noisy" and you will get heterodynes when tuning.
>
>If I have a station tuned in, just moving the tuning dial 0.5 Khz
>will result in noise or static in the speaker, sounding like a
>dirty pot.  Additionally, the station may jump in frequency or
>all together not be heard.  Rocking the VFO back and forth with
>produce the scratchy noise and cause loss of the station at
>times.  If I tune a station and just leave the radio alone, it
>receives fine, with good audio and signal strength.  But if I
>touch the VFO knob, I get the noise and loss of station and
>sometimes heterodynes.
>
>I have removed all the pcb's and "retinned" the copper tracks so
>they make good ground contact, and I have tried terminating the
>output of the LMO with 47 ohms with no luck.
>
>Any ideas out there?  Sure would like to get this radio working.
>
>Thanks
>
>Jim
>
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