Drake R-4B receiver alignment question.
 

I was aligning a Drake R-4B receiver. When aligning the receiver
sensitivity and the S meter the manual states to set the RF gain to
read -15 volts from TP2 (test point 2). The manual states to set the
meter to S40. At -15 volts the highest I can get my meter to go is
S20. I replaced every tube in the receiver except the first RF amp,
and the only reason I did not replace that tube is because I don't
have one of those tubes at this time.
The alignment instructions for this section are on-line at;

http://www.wb4hfn.com/DrakeManuals/R...ual_R4B_38.jpg

The full Drake R-4b manual with schematic is on-line at;

http://www.wb4hfn.com/DrakeManuals/R4B/Manual_R4B.htm

Any ideas why the S meter will not go to S40?

First check R9 and R13 both 1.5K make sure they haven't changed
Go back and touch up T6 and T7
Then check if the sens control R40 reads 1K across
That should correct your full scale if your 1rst RF tube is OK.
73 Chris VE3NGW/W4 Florida

Real Radios wrote:

I was aligning a Drake R-4B receiver. When aligning the receiver
sensitivity and the S meter the manual states to set the RF gain to
read -15 volts from TP2 (test point 2). The manual states to set the
meter to S40. At -15 volts the highest I can get my meter to go is
S20. I replaced every tube in the receiver except the first RF amp,
and the only reason I did not replace that tube is because I don't
have one of those tubes at this time.
The alignment instructions for this section are on-line at;

http://www.wb4hfn.com/DrakeManuals/R...ual_R4B_38.jpg

The full Drake R-4b manual with schematic is on-line at;

http://www.wb4hfn.com/DrakeManuals/R4B/Manual_R4B.htm

Any ideas why the S meter will not go to S40?

Did you set the zero adjust to S1 with the antenna
disconnected first? In reality, on many bands there
may be anywhere from s1-s9 noise level with the
antenna connected. It is probably set too low.

Actually you need to go back and forth between the two
adjustments, and there will be some warm-up drift.

Nice radio!


"Real Radios" wrote in message
...


I was aligning a Drake R-4B receiver. When aligning the receiver
sensitivity and the S meter the manual states to set the RF gain to
read -15 volts from TP2 (test point 2). The manual states to set
the
meter to S40. At -15 volts the highest I can get my meter to go is
S20. I replaced every tube in the receiver except the first RF
amp,
and the only reason I did not replace that tube is because I don't
have one of those tubes at this time.
The alignment instructions for this section are on-line at;

http://www.wb4hfn.com/DrakeManuals/R...ual_R4B_38.jpg

The full Drake R-4b manual with schematic is on-line at;

http://www.wb4hfn.com/DrakeManuals/R4B/Manual_R4B.htm

Any ideas why the S meter will not go to S40?