[RFI] RFI & Alternator Replacement

[qrv at kd4e.com]

Awesome, perfect, that's exactly what I needed to know and to
understand.

Thanks Chris!

73, DavidC KD4E

> An old school externally regulated alternator with a _mechanical_
> regulator is very, very noise.
> 
> This is because there is a electromechanical "vibrator" pulsing the
> field coils.
> 
> If you have an external regulator that buzzes, go straight to the
> auto-parts store and get a solid state replacement (simple analog
> control loop, no pulsing).
> 
> I had to do this for the 74 ford trunk I picked up this summer.
> 
> Any modern internally regulated alternator should have a solid state
> analog regulator.
> 
> 6 v.s. 12 diode...12 spreads the load and is generally a sturdier/mor
> reliable alternator.  IIRC, a dual bridge may or may not produce less
> ripple depending on internal construction of the alternator itself.
> 
> 
> 1 wire v.s. normal....
> 
> 
> One wire alts depend in residual magnetism to self-excite.
> 
> Normal alts take an ignition switched power feed to start the alternator
> then self-excite after that.
> 
> If a one wire sits long enough it will not self-excite...And you need to
> pull a cover and feed it power to start it up.
> 
> 
> If you have a 80s GM you already have a "standard" alternator with a DC
> + output and a 2 pin connector.
> 
> 
> By all means, get a dual bridge high wuality internally regulated
> alternator, but get a standard type not a one wire.
> 
> If you look at the listed vendor, they have similar dual bridge non one
> wire models with a std GM connector...get one of those.  Inspect the 2
> wire connector, if corroded you can get a replacement for < $5 and just
> about any auto parts store.
> 
> _Carefully_ connecting a 1uF high current rated cap in parallel with a
> 1000pf cap between the alt output post and case ground will greatly
> reduce ripple as well but you must be CAREFUL as this is a 70-250 amp
> alt output.
> 
> And remember to replace the alternator cable if you oversize...A 80amp
> factory alt may one have 8 or even 10 gauge wire for a charge lead.  I
> just replaced a 2ft 10ga charge lead with 4ga.  IIRC mid 80s GM
> trucks/subs had a 8ga charge lead, marginal for a 140amp or better
> alternator (I had a 1984 3/4t Suburban with a 350 and a 170amp
> alternator around 2000 or so)
> 
> 
> Again, if you need to ask about a one wire, do not use...eventually it
> will fail to self excite and you will not automatically know how to
> revive...One wires are for the parts built street rod, IF you are too
> lazy to run a single 16ga ignition switched lead...And in your case you
> can get a drop in unit as your rig already has the wiring.
> 
> 
> 
> On 9/21/17 17:46, qrv at kd4e.com wrote:
>> Is a dual-bridge rectifier, as described here re. efficiency
>> and durability http://faqs.alternatorparts.com/ also a better
>> choice versus RFI or no?
>>
>> I just read through this http://www.k0bg.com/alternator.html
>>
>> And am looking at these
>> https://alternatorparts.com/10si-12si-high-output-alternators.html
>>
>> Thanks - DavidC KD4E
>>
>>> Is there any difference in the type of alternator installed
>>> and mobile RFI?
>>>
>>> I'm looking at this for my 1986 Suburban:
>>> https://play.google.com/store/apps/details?id=ngd.p_0001
>>>
>>> Is a "self-exciting" 1-wire design potentially problematic?
>>>
>>> If so - your recommendations, please?
>>>
>>> And, no, I could care less about the chrome.
>>>
>>> Thanks & 73, DavidC KD4E