Initially installed a 5.6pF ceramic their. Treble okay.
Then I placed a 10pF ceramic. Treble okay.
Then placed 100pF/2KV. Treble okay.
Now it's 22pF. Treble okay.
470pF? Don't know.
edit: No audible RF modulation noise in any of the above cases, even with my standing-wave RF exciter turned on.
Then I placed a 10pF ceramic. Treble okay.
Then placed 100pF/2KV. Treble okay.
Now it's 22pF. Treble okay.
470pF? Don't know.
edit: No audible RF modulation noise in any of the above cases, even with my standing-wave RF exciter turned on.
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Which of the Grounds in the schematic need to be connected to the Signal Ground?
The one closest to the ground supply connector, as short as possible. No 10ohm elevation is used.
Dear Shaan/LazyCat
How about replacing BD139/140 with SC3423/2SA1360/? i found it in my local store.
is there any part to change?
thanks
Checked the specs for them. 3423/1360 should be okay.
Edit: You may need to re-drill the holes for the VAS bjts a little wider. Like the ones for the electrolytic capacitors.
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Dear Shaan/LazyCat
How about replacing BD139/140 with SC3423/2SA1360/? i found it in my local store.
is there any part to change?
thanks
2SC3423/2SA1360 are very good transistors for VAS, but they have Ic max=50 mA, so VAS bias current should not exceed 15 mA to have some reserve to max collector current limit.
Also current gain of 2SA/SC is linear only to some 20 mA than it drops rapidly, but for the VAS purposes in SSA they should work without any modification.
Ok, thank you Shaan i'll redrill holes for VAS.Checked the specs for them. 3423/1360 should be okay.
Edit: You may need to re-drill the holes for the VAS bjts a little wider. Like the ones for the electrolytic capacitors.
Thank you very much LC for complete explanation, i learn something new.2SC3423/2SA1360 are very good transistors for VAS, but they have Ic max=50 mA, so VAS bias current should not exceed 15 mA to have some reserve to max collector current limit.
Also current gain of 2SA/SC is linear only to some 20 mA than it drops rapidly, but for the VAS purposes in SSA they should work without any modification.
yes, i use FeCl to etch my boardHi naf.
Do you use FeCl to etch the PCBs?
Here it is my complete shaan's SSA peeceebee...
Hi naf, with what did you coat PCB?
Here it is my complete shaan's SSA peeceebee...
was it silver coated? have you done it manually? It looks like factory coated...very refined!
I coat using immersion silverHi naf, with what did you coat PCB?
Thankyou,was it silver coated? have you done it manually? It looks like factory coated...very refined!
yes it's silver coated. all peeceebe process have done manually.
i enjoy all processing step. it's Do it Myself .
Thankyou,
yes it's silver coated. all peeceebe process have done manually.
i enjoy all processing step. it's Do it Myself .
Are you doing actual silver nitrate bath electroplating?
I saw one DIYer silver coating his pcb in You Tube , it looks complicated though mixing these 3 types of chemicals, it looks like a chemist job
Naf, what is this immersion silver you mentioned, can this product be purchased locally? I have read silver nitrate is very expensive.
Naf, what is this immersion silver you mentioned, can this product be purchased locally? I have read silver nitrate is very expensive.
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