I did a voltage and resistance check against the table in the manual just to see if there was anything way off. Surprisingly, the case of the output transistor was at 10.3v instead of 12.5v. Perhaps that's why audio isn't ear blasting. I'll have to investigate further. As far as the resistance checks, everything was within reason for a 35 year old (perhaps older) radio, except for the resistances around V3, the mixer and VFO. Pin 3 is supposed to be 330 ohms and I measure .6 ohms. Pin 7 is supposed to be 7k and I measure 1m. Should I believe the chart in the manual? The VFO certainly seems to work fine. With those measurements so far off, I wouldn't expect the receiver to be so operational, except for the S-meter.
I guess I'll dive deeper and try and understand why those couple resistance measurements are so far from what's listed in the chart.
Tom n7tm
On 10/11/06,
Jason Buchanan <[EMAIL PROTECTED]> wrote:
Tom Taylor wrote:
> The receiver receives well, but the S-meter is extremely stingy. A
> very loud SW broadcast station may only read S5.
>
Will be interested to hear what you find out... I have an R-4 that
exhibits the same on its S meter. It receives fine but with max CCW the
needle reads about +50dB. I went back and recalibrated it as it should
be which made the AGC sound as a Drake should. If the recv sens or S
meter sens is off you will not have the best sounding AGC action (thumpy).
One other thing to try is replacing the 12BZ6. If it's weak the dynamic
range will be low.
thanks
--
73 Jason N1SU
Jason Buchanan - Boxboro, MA
Website: http://n1su.com/
