From general circuit design principles, I agree that in A2A1, Q9 (2N2907A) should be drawn as a PNP transistor with the emitter at the top, similar to Q5 (which should be a 2N2907A also). But I also see some other likely errors:
(1) C1 (390 uF) and C2 (47 uF) are shown in a Pi network low pass filter on the 10 MHz (doubled 5 MHz drive) signal. My guess is that the value of C1 is likely 390 pF and C2 is 47 pF. A value of 3.3 nH for L5 seems reasonable.
(2) C26 is shown as 750 uF, but is likely 750 pF (to match C19, which also resonates with a 33 nH inductor).
(3) There are two C28's shown. The one resonating T2 should probably be 15 pF (rather than 15 uF).
(4) There are two C3's shown. My guess is that the capacitor at the junction of Q9 and R7 should be labelled C23.
--
Bill Byrom N5BB
On Mon, Dec 25, 2023, at 6:41 PM, Jim Harman via time-nuts wrote:
In the A2A1 schematic, Q9, 2N2907A, is a PNP transistor. The emitter and
collector are reversed in the schematic.
I would guess that Q5, shown as 2N2902A, is also a 2N2907A.
On Sat, Dec 23, 2023 at 10:07 PM Perry Sandeen via time-nuts <
time-nuts@lists.febo.com> wrote:
List,
I have re-drawn 4 Symetricon 1050A schematics from scans provided by John
K0CGJ using PSE 9 into PNG images. These images can be enlarged to any
size for printing without smearing.
I'll try attaching them to this post. If they are scrubed, please contact
me off line and I'll be glad to send them.
If anyone has other schematic scans, please send them to me and I'll
re-draw them into TIFF BIT images for the ability to make large clear
prints.
If anyone discovers any error's, please contact me so I can correct them.
Best wishes,
Perry KM6FQV
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
From general circuit design principles, I agree that in A2A1, Q9 (2N2907A) should be drawn as a PNP transistor with the emitter at the top, similar to Q5 (which should be a 2N2907A also). But I also see some other likely errors:
(1) C1 (390 uF) and C2 (47 uF) are shown in a Pi network low pass filter on the 10 MHz (doubled 5 MHz drive) signal. My guess is that the value of C1 is likely 390 pF and C2 is 47 pF. A value of 3.3 nH for L5 seems reasonable.
(2) C26 is shown as 750 uF, but is likely 750 pF (to match C19, which also resonates with a 33 nH inductor).
(3) There are two C28's shown. The one resonating T2 should probably be 15 pF (rather than 15 uF).
(4) There are two C3's shown. My guess is that the capacitor at the junction of Q9 and R7 should be labelled C23.
--
Bill Byrom N5BB
On Mon, Dec 25, 2023, at 6:41 PM, Jim Harman via time-nuts wrote:
> In the A2A1 schematic, Q9, 2N2907A, is a PNP transistor. The emitter and
> collector are reversed in the schematic.
>
> I would guess that Q5, shown as 2N2902A, is also a 2N2907A.
>
> On Sat, Dec 23, 2023 at 10:07 PM Perry Sandeen via time-nuts <
> time-nuts@lists.febo.com> wrote:
>
> > List,
> > I have re-drawn 4 Symetricon 1050A schematics from scans provided by John
> > K0CGJ using PSE 9 into PNG images. These images can be enlarged to any
> > size for printing without smearing.
> > I'll try attaching them to this post. If they are scrubed, please contact
> > me off line and I'll be glad to send them.
> > If anyone has other schematic scans, please send them to me and I'll
> > re-draw them into TIFF BIT images for the ability to make large clear
> > prints.
> > If anyone discovers any error's, please contact me so I can correct them.
> > Best wishes,
> > Perry KM6FQV
> > _______________________________________________
> > time-nuts mailing list -- time-nuts@lists.febo.com
> > To unsubscribe send an email to time-nuts-leave@lists.febo.com
>
>
>
> --
>
> --Jim Harman
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
