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KB2VXA > ALL 08.09.13 14:59l 61 Lines 3276 Bytes #999 (0) @ WW
BID : 43782_VK6ZRT
Read: GUEST
Subj: Re: VK3API > radio power lead issues
Path: IZ3LSV<IK2XDE<ON4HU<CX2ACB<XE1FH<VE3UIL<VK6ZRT
Sent: 130908/1301Z @:VK6ZRT.#BUN.#WA.AUS.OC #:43782 [Boyanup] $:43782_VK6ZRT
From: KB2VXA@VK6ZRT.#BUN.#WA.AUS.OC
To : ALL@WW
Hi Tony and all,
This being an open forum I write for the benefit of the few left who may not
be as up on technical stuff as we old farts. A few observations that
initially caught me by surprise
Those 3AG in line fuse holders are the devil's own invention designed to
frustrate us. There are plenty of reasons, the most common being they're
completely unsuitable for automotive applications and the only reason why
Amateur Radio manufacturers use them is because they're cheap. Then they turn
around and sell us radios worth a king's ransom. <slow burn in progress>
That's why I change them out for Max fuses and holders like what come on
commercial rigs (they're smart, not cheapskates) being they're dirt, oil and
water proof PLUS contact blades have lower resistance enabling them to handle
high current without significant heating.
Then you rather duplicated my comments about "earthing" the negative battery
terminal, but how do you earth when there is no earth? Yeah, the same way you
ground when there is no ground. Language is silly... idnit? (;->) Alright,
negative return to be correct but that sounds like somebody's no refund
policy and I'm getting rediculous. Well, the point is if engine starting
current is forced to go through those thin grounding straps they'll go up in
a flash and so will the radio so the only way to protect it is to make sure
the heavy lead from the B- terminal is firmly secured to the engine block
near the starter. The rule here is the transistor is there to protect the
fuse, not the other way around.
That's the correct practice, both radio leads directly to the battery and the
positive ONLY fused AT the battery. Anything else tends to introduce
electrical noise at least, improper operation at worst. I too had a rig
suddenly go wonky and I couldn't figure it out for the life of me. Then I
stumbled upon a blown fuse in the negative lead, I have no idea how that
happened since there was no discoloring inside the glass tube nor was the
break visible being up inside an end cap. Eh, ours is not to wonder why, ours
is but to fix it and get the L out of here. (Taken from Charge Of The Shop
Mechanic.)
Eh, that's not alternator whine you hear when you start the engine, the
alternator is barely turning. That's the ripple caused by the starter motor
drawing such current it causes AC currents to be created across any
resistance the DC current encounters. It's an audible indication you're
torturing the radio with all sorts of electrical hash that doesn't do it any
good. The best thing to do is turn off the radio before the engine and turn
it on after it has started. (Cue The Buggles; Laziness Killed The Radio In
Your Car.)
Oh don't blame the Australian climate, blame Amateur gear manufacturers for
taking the cheap way out by not getting ISO 9000 certification and not
building equipment to those standards. Commercial and mil surplus gear is ISO
certified and well worth it BTW, when it's guaranteed to work from -35C to
135C you know it'll work anywhere on the planet, even in New Jersey.
73 de Warren
Station powered by JCP&L atomic energy, operator powered by natural gas.
Message timed by NIST: 08-Sep-2013 at 12:53 GMT
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