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KID RF Hash

Started by Tobit, June 05, 2020, 01:57:22 PM

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Tobit

Quote from: Vic on June 06, 2020, 07:09:34 PM
Poked around on the Web,   for reviews,   the following one popped up:
http://www.w0qe.com/N8XJK_battery_booster.html

Wow, that is 12 years old. A lot of improvements have been made since.  Looks like he did some solid testing, I will read it in more detail tonight anyway. Thanks!  This one I'm looking at is a brand new version and hasn't been released yet, they are anticipating shipping in July.

QuoteThe main reason that we built this off-grid location,  was due to the desire/need to get away from ALL of the ever-increasing broadband noise sources,  in town.

We are only about 5 - 6 miles away from the power grid,   and it is quiet.  Our power system makes some noise,   but  it is at a very low level,  compared to in-town.
Same here, it is very quiet.  Right now the only noise is being generated by the KID but I know I can get that knocked down eventually.

Tobit

Coming out of the KID, I run two short 10 ga. leads to powerpole connectors so I have a quick disconnect before the 12" run to the breaker box.

Should I stack two of the 3" ID mix 31 rings and wrap as many turns as I can on BOTH the battery and PV leads coming out of the KID on the same core?  Or should I use a separate core on each set of leads?

Vic

Quote from: boB on June 05, 2020, 05:27:34 PM
Quote from: Tobit on June 05, 2020, 03:35:38 PM
Honestly, it isn't that bad but I moved to the middle of the woods so I'd have no noise so I'd like to clean it up as much as possible.  :)

   ...   Ferrite common mode chokes on the battery and PV input lines are the first thing to try like Vic mentioned.  Right next to the Kid.  As close as possible.

If you have a large enough toroid, I would run both battery and both PV lines through the same toroid if it is large enough.

Keep us posted.
K7IQ

Hi Tobit,

I  have always used separate toroids for PV in,   and CC to battery cables.   But,  boB did mention using a single core for both,  it you can make that work.

A 3" ID core is large,  but there should be no problem getting a lot of turns of your 4 conductor with that core size.

I got some of those 4" OD,  3" ID cores for use with large cable.   You may not need cores that are that huge,  on your system.

Sorry for the ambiguous,   kinna not an answer,  answer.   Later,   72   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

ClassicCrazy

My solution for a constant 13.8v is to have 24v battery and then use a Samlex 24 to 13.8v converter.  You also get the advantage of being able to get more power out of your Kid that way too and use smaller gauge wires compared to 12v.  The Samlex converters are not too expensive - less than a switching power supply would cost.

Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

Tobit

Quote from: ClassicCrazy on June 06, 2020, 10:37:37 PM
My solution for a constant 13.8v is to have 24v battery and then use a Samlex 24 to 13.8v converter.  You also get the advantage of being able to get more power out of your Kid that way too and use smaller gauge wires compared to 12v.  The Samlex converters are not too expensive - less than a switching power supply would cost.
Upgrading the 400AH battery bank to 24V is very expensive however.

boB


Interesting about that booster.  It's like an MPPT controller in reverse and with the keying feature so it only runs when transmitting...

Personally, I wouldn't use one.  I would buy more/better battery for the job.  Allowing the battery to run that low could hurt the battery.  And I don't believe the 5 extra hour run time unless he was just receiving most of the time.  A battery that is 10.5 volts is dead.

In the link that Vic posted, that toroid sure looks kinda like the size of toroid I posted a picture of.

I would try and run ALL 4 power wires through the same toroid.  That way,  it will help insure that not common mode noise goes through one of the wires that are NOT going through that toroid but through the 2nd or 1st toroid.

Another thing to remember is that although wrapping more than one turns through the toroid is better, there can come a point where too may turns make it worse due to capacitance bypassing the filtering action from one side to the other side of the toroid.  So, if you can get 2 or three turns, that should be good.

If you don't get some RFI reduction with say, 2 turns, you probably won't get much more with 3 turns.  Not guaranteed anyway.

Also, place the toroid as close to the Kid as possible.
K7IQ 🌛  He/She/Me

Tobit

Quote from: boB on June 06, 2020, 10:52:10 PMPersonally, I wouldn't use one.  I would buy more/better battery for the job.  Allowing the battery to run that low could hurt the battery.  And I don't believe the 5 extra hour run time unless he was just receiving most of the time.  A battery that is 10.5 volts is dead.
I never would run the battery that low either.  In fact, in my DC circuit running all the devices, I have a low voltage disconnect configured to shutdown at 11.8V.  You are probably right, I don't need it.  My 7300 seems to do fine even when the bank dips a bit low on transmit.

Back to the ferrites,  I'm trying to decide between that inexpensive Fair-Rite 2631626202 or a stack of two of the 3" ID.  Should I try the less expensive first?  I'd like to do two turns of 4-wire 10 ga. ideally.

Thanks again.


Vic

#52
Hi Tobit,

On the ferrite,   why not try the smaller core (2631626202) to see what happens.  Would guess that 4ea #10 AWG THHN cables would fit easily,  even with three turns.

Speaking of turns,   am sure that you know,  that the first pass through a core (without a loop back),   is counted as one turn.  Turns are the total number of passes through a core.

Why not take three loops (passes)  of the 10 Ga wire that you will be using,  tape them together tightly,  to estimate if that number will fit through the 1.00" ID  of that candidate core.   You might want to try two  turns,  vs three turns,  so you might leave enough cable to make that extra turn.

Also,  the intensity of the RFI signal should be in proportion to the output current of the KID,   so try to keep that fairly constant when doing comparisons of differing approaches.  As noted previously,   place the core as close to the KID as possible.

All IMO,   73  GL,  please let us know how things are going.   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Tobit

Not to veer too fara off-topic, how would the RFI be on a PWM controller such as the Brat! compared to MPPT's such as the Midnite's KID and Classics?  My KID is about maxed out with 3x 150W panels and I don't want to buy another KID or switch to a Classic just yet.  However, I have a spare Brat! on the shelf along with a panel I'd like to wire into the bank.  Would I be fighting too much hash?

Vic

Tobit,

PWM  CCs,  like the Brat,  should be much quieter,   RFI-wise.   They still do switching,   but this should be quite tame,   compared to MPPT CCs.   Also  the Brat would be handling a lower power (lower current)  than does your KID.

Some PWM CCs do have a low RFI  mode that is said to reduce,  further,   any RFI from standard PWMing.    Do not know it the Brat has this function.

FWIW,   VIc
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Vic

Hi Tobit,

The Brat manual says the following:
S1-8 PWM DISABLE - Slide switch up for On/Off charging - Reduces EMI. Not recommended.

Looks like the Brat would be worth a try as an auxiliary CC.  Perhaps  if needed,  you could switch the KID to OFF,  if you really needed QUIET,   and the Brat  could do some charging during the day  …

FWIW,   Vic
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Tobit

Vic and boB,

Since it is very overcast here today, my KID is switching frequently between Resting and BulkMPPT.  Attached is a recording of the hash and birdie.  Since 6M is completely dead here right now, you can hear the hash while Resting and then the birdie while in Bulk.  This matches the Resting and Bulk photos I posted earlier.

I have that Fair-Rite bead on the way, just ordered today from DigiKey.

73

Vic

Tobit,

The recording appears to have a very faint  tick tick  tick  tick tick tick in the background,   early,   and then the "birdie".

If the tick,  tick sound is coming from your RX,  then it sounds like the Converter is running,  which is unusual for a Resting MN CC.  Perhaps it is another SMPS in the KID   â€¦   perhaps a power supply that runs the electronics in the CC (?).

The "birdie"  sounds very pure  --  no modulation to speak of.   Most carriers,  or birdies  from the Classics (and the OB MX-60)  CCs  have a lot of modulation (racket) on the carriers.   The more work that the CC is doing,   the louder the racket.   But,  maybe,  if the KID was working harder,  the pure-ish carrier would have more hash on it,   or  maybe,  your RX was in a Digital mode,  with a fairly/very narrow filter   â€¦   dunno.

The KID here,   is on a back-up 12 V system,   so have not studied its noise profile.

Fine on having that ferrite on its way.   73   Thanks for the info,  Vic   
Off Grid - Sys 1: 2ea SW+ 5548, Surrette 4KS25 1280 AH, 5.25 KW PV, Classic 150,WB, Beta Barcelona, Beta KID
Sys 2: SW+ 5548s, 4KS25s, 5.88 KW PV, 2 ea. Classic 150, WB, HB CC-needs remote Monitoring/Control, site=remote.
 MN Bkrs/Bxs/Combiners. Thanks MN for Great Products/Svc/Support&This Forum!!

Tobit

Vic,

I've isolated it farther.  Upon resting, the hash appears to be coming from the PV array, it is lessened when I turn off the PV breaker to the KID but a little remains on the waterfall..  The birdie is definitely a result of the KID in Bulk.

Definitely need to get that ferrite here.

boB

Thanks for the recording.

The click I think that Vic is referring to sounds kind of like a beat-note to me. 

I think it stops wavering or beating near the end of the recording ?

So, what was the approximate S meter reading during that recording and the background reading ?

Seems like there was almost no background noise.

boB
K7IQ 🌛  He/She/Me