Jacques, perhaps this was a manufacturing efficiency, such that the
"identical" assembly could be interchanged between position "1, and position
"2" during assembly. I was surprised to discover this detail on the non-used
pins.
Yes - I have now completed replacing all "bumblebee coded" leaky caps (these
measured >1% leakage), the picture was before component level work started.
I have also completed the resistor drift change out, and I have installed the
new "high-Q" dipped silvered mica capacitor (C327) across the primary of T207
(retaining the old just in case).
making progress!
John
On Wednesday, July 10, 2024, 3:09:59 PM EDT, Jacques Fortin
<[email protected]> wrote:
John, these non-used pins are linked to the fact that the Z201-1 and Z201-2
are identical, and etc. for the other Zxxx.
These are non-used pins when they are in position "1" but used when they are in
position "2".
From the picture you sent, I see three "bumblebee coded" PIO caps in there.
Did you plan to change those ??
All the ones I had were found leaky....
73, Jacques, VE2JFE in Montreal
-----Message d'origine-----
De : [email protected] <[email protected]> De la part
de jkharvie via R-390
Envoyé : 10 juillet 2024 13:46
À : R-390 Mailing List <[email protected]>
Objet : [R-390] Guided discovery on the RF deck
While in the RF-subschassis process of cleaning and reassembly I noted that
only 2 of three pins are plugged in and active on
Z201-1Z202-1Z203-1Z204-1Z205-1Z206-1
as per the electrical schematic, but something I never specifically noted or
thought much about previously.
This got me thinking that the non-used pins might serve as a source of spare
pins if/when needed.
Attached graphic shows top view of the RF subchassis awaiting cleaning, a three
pin "can" of which two pins are used, a bottom view showing mounted cans with
no connection to the one pin in highlighted red box, and the RF subschassis
schematic showing all of this.
One of the "tools" I made was drilling out the end of a bamboo chopstick with a
#35 drill (0.110") to hold 1/2 of cotton tip applicator swab.
Best regards,
John (N3JKE)
______________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
