Re: Grounding shematic for a Metal Chassis, which is the right way to wire up?


Tim Gorman
 

Respectfully, having fought noise problems in several different cars
and trucks, dependence on the dash to provide a ground or even
depending on the floor pan of the vehicle is a good way to introduce
noise into the rig. Not all body parts are properly connected together
and then connected to the battery and physical stress during car
movement can cause noise generation because of high resistance grounds.
Similar to single point grounds in places like telephone switches or
power substations, a negative lead from the radio directly to the
battery has always worked best for me.

tim ab0wr

On Fri, 7 Sep 2018 09:40:13 -0700
"iz oos" <and2oosiz2@gmail.com> wrote:

Ok. Think to an audio amplifier in a car. Often you need just the red
wire to turn it on. When the metal case of the amplifier is connected
to the chassis of the car which in turn is connected to the negative
of the battery (please correct me if I am wrong, I think it is
correct). If you add another ground wire (the black in our example)
is a nuisance that may make a ground loop. The same applies in the
uBitx, if the case is all metal some wires are nuisances that may
lead to ground loop issues.

when use metal case then jack sleeves have ground at case an yellow
wire isn't need any more and use thick black ground wire and and
and..then big written 'be aware of ground loop

Il 07/set/2018 17:50, "iz oos" <and2oosiz2@gmail.com> ha scritto:

Not in Germany but not that far away, I have qsos on VHF with German
stations only during contests with big big stations like DR9A... I
mostly use qrp and minimal equipment on higher bands as well. Not
every time an increase of noise level is due to ground loops. But it
happened to me I solved noise issue using for instance isolating
audio transformers between the rig and external accessories and
especially PC soundcards. My case is all metal except for the front
and the back panels so it is surely different from yours. I didn't
notice annoying noise that could be due to ground loops. All
installations are different. Ground loops may become a problem when
too many things are connected together and are not bond together to a
common ground point. I am not an expert on this, read the ARRL or
equivalent handbooks that treat this topic.

Il 07/set/2018 16:36, "sdr freak" <sdrfreak55@gmail.com> ha scritto:

ok thank you!

would you life in germany, too? if yes, we should try to transmit
with the vhf radio when you want it too?

ok by the way, in your post you mean the increased noise is a sign
of ground loops.. ok something new i have learned by this.. very
thankfully about these kind of knowledge!

when the ground loops you say, isn't the problem in ubitx by wire
up the v1.9 shematic in a metal/aluminum case without extra ground
cable to the case and less cable for the sleeves, how i should i
understand the words in shematic v1.9 which says the things that
makes me crazy.. there is written when use metal case then jack
sleeves have ground at case an yellow wire isn't need any more and
use thick black ground wire and and and..then big written 'be aware
of ground loops'...

this is the problem i doesn't understand and how have you make your
project by this, by the using of or not using these whole points
sayes in shematic v1.9? you dont have a metal box only front is
metal ?

hm here again the shematic v1.9 which i have to understand..
https://groups.io/g/BITX20/photo/49276/0/uBITX_wireup_v1.9.
png?p=Name,,,20,1,0,0



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