Are we talkin' about a AC-to-DC converter here, or a DC-to-DC? Seems like the first few posts refer to the old AC-to-DC converters you'd find on old travel trailers and S&S MHs. Seeing how you have a Silversides, I'm going to think it's an AC-to-DC.
While there are a few nice converters out there, made by Progressive Dynamics, etc. that have 3-stage charging and decent electronics (for $250 or so), I too would vote for a quality charger. Better yet, a nice marine or RV inverter-charger can be had for less than $1000 used.
I used to think I could get by on mostly DC... but when my new coach came with a good inverter charger (and Link panel system), I found it truly changed the way we camped. If we avoid air conditioning, we can easily go a weekend dry-camping somewhere w/o firing up the genny at all. Making coffee, running the microwave, and running big AC fans to keep the air moving.
Back to your original question, though, go ahead and use a digital voltmeter on your output and see what kind of voltage it's putting out. See if it's stable and less than 14v, since even a 3-stage charger will frequently hit 14v to keep batts in prime condition. One thing it won't measure is the quality of the power and its regulation. Cheaper converters put out a lot of noise (like RF). Worse, they might
simply do a 1:10 step-down... 120v = 12v, 110v = 11v, etc., so low park power might mean low voltage to your DC items... and probably worse than over-voltage in terms of heat and amperage draw. I'm no EE, so this 1:10 "theory" is just a WAG (wild a*s guess)†
, however... so check it with a meter.
Also see how it's supposed to be wired. If your DC circuits are wired "downstream" of the battery, I'd think that the batt would be required to "filter" the loads. If the battery is on a separate line feed, the battery would only be used when the converter's not converting... I think (refer back to the "I'm no EE" phrase above†
Whatever you do, Dave, please keep your beautiful Silversides on the road. Makes me feel good to know you're out there driving such a classic creature!