Re: 64 conv. missing some capasitors
You mean that the body construction is a non-issue when it comes to conducted noise, right?
Yep, that's what I said...
This thread has me wondering why they didn't eliminate some or all of these capacitors by simply filtering the 12 Vdc inside the radio? I work in avionics, I see filtered 28 Vdc power supplies quite often.
Hum, you'd flunk basic electrical design 101 with that approach...
The rule of thumb is to 'hush up' noise at its source. Why?
Do you really know how many RFI susceptible loads are downstream? Do you want to add cost by filtering each RFI susceptible circuit individually?
How big of a filter do you build into the RFI susceptible load? What if the circuit geometry is 'just right' and that load is sitting at a resonnance point for standing wave reinforcement?
Those are the common reasons behind the designer's creed of addressing noise at the source...
BTW, the radio DOES have a very simple, low pass filter built into it.
Also, just for grins, how many of these capacitors does a 64 have and what are they connected to? I assume that's in the AIM, but I don't have one for a 64.
Ah, I can't spoil the 'mystery' for you... That's the mystery that awaits the arrival of your copy of the AIM book and you're opening it to the radio option section in the back where each of the RFI caps associated with the radio are called out!
You mean that the body construction is a non-issue when it comes to conducted noise, right?
Yep, that's what I said...
This thread has me wondering why they didn't eliminate some or all of these capacitors by simply filtering the 12 Vdc inside the radio? I work in avionics, I see filtered 28 Vdc power supplies quite often.
Hum, you'd flunk basic electrical design 101 with that approach...
The rule of thumb is to 'hush up' noise at its source. Why?
Do you really know how many RFI susceptible loads are downstream? Do you want to add cost by filtering each RFI susceptible circuit individually?
How big of a filter do you build into the RFI susceptible load? What if the circuit geometry is 'just right' and that load is sitting at a resonnance point for standing wave reinforcement?
Those are the common reasons behind the designer's creed of addressing noise at the source...
BTW, the radio DOES have a very simple, low pass filter built into it.
Also, just for grins, how many of these capacitors does a 64 have and what are they connected to? I assume that's in the AIM, but I don't have one for a 64.
Ah, I can't spoil the 'mystery' for you... That's the mystery that awaits the arrival of your copy of the AIM book and you're opening it to the radio option section in the back where each of the RFI caps associated with the radio are called out!
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