Hi,
Installing a Spectrum Communications UK40 & -40 EPROM SC02B board and as part of the "-40" band connections the instructions say to cut round pins 7, 8 and 9. On the track to which the pins 8 and 9 are both connected there is a 47uF electrolytic, a zener (MZ205) and a 0.047 cermaic cap. Do these components need to remain connected to pins 8 and 9 (and even pin 7) after cutting or are they serving another part of the circuit or do they become redundant if I am to simply cut around pins 8 and 9?
Link to Major 588 schematic: http://www.cbtricks.com/radios/major/m5 ... 8-5_11.pdf
Thanks!
Major 588 - adding UK40 & -40
- Phuture
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Major 588 - adding UK40 & -40
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- 14CS06
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Re: Major 588 - adding UK40 & -40
Hello
What is your PCB :
PTBM059COX
http://ham-internationa.webmo.fr/Schema ... 059COX.pdf
PTBM121D4X
http://ham-internationa.webmo.fr/Schema ... TOS012.pdf
http://www.ham-international.com/cybernet.htm
@+
Claude
What is your PCB :
PTBM059COX
http://ham-internationa.webmo.fr/Schema ... 059COX.pdf
PTBM121D4X
http://ham-internationa.webmo.fr/Schema ... TOS012.pdf
http://www.ham-international.com/cybernet.htm
@+
Claude
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- Phuture
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Re: Major 588 - adding UK40 & -40
Hi Claude,
Thanks for the links. It's the PTBM059COX board (as provided in the schematic link in my OP). I would think the cuts go directly round 7,8 and 9 but just trying to understand the function of the other components on that line.
Thanks!
Thanks for the links. It's the PTBM059COX board (as provided in the schematic link in my OP). I would think the cuts go directly round 7,8 and 9 but just trying to understand the function of the other components on that line.
Thanks!
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- Mitch
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Re: Major 588 - adding UK40 & -40
Those 'other components' are the voltage regulator circuit for the PLL, so are very necessary. You need to isolate pins 7, 8 & 9 because they're channel switching inputs not normally used but are needed to drop frequency/band to the -40 channels, the output from the eprom board connects to them but they need to be seperated from previous connections else it won't work properly. Just make sure the pins are isolated and the other connections are maintained using links if you need to, you wouldn't want to break the PLL chip.
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Re: Major 588 - adding UK40 & -40
Got it. Thanks Mitch - much obliged.Mitch wrote: ↑16 Oct 2022, 13:46 Those 'other components' are the voltage regulator circuit for the PLL, so are very necessary. You need to isolate pins 7, 8 & 9 because they're channel switching inputs not normally used but are needed to drop frequency/band to the -40 channels, the output from the eprom board connects to them but they need to be seperated from previous connections else it won't work properly. Just make sure the pins are isolated and the other connections are maintained using links if you need to, you wouldn't want to break the PLL chip.