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[KK6TBF]

in my defender I have a 100w renogy panel mounted to the exo cage. in front of the driver's side corner of the panel about 3" away I have my larsen NMO270B antenna. the kenwood is connected to my auxiliary lithium battery.  the lithium battery is connected to a redarc manager 30 which is a battery manager featuring DC-DC, solar, and 110V inputs to charge the battery.  the redarc has a remote display panel that shows the condition of the battery and the charging status.  it shows how many solar watts its taking in, how much power is going into and out of the battery (shunt on the negative terminal of the lithium).

today i was testing the radio (which works fine) and i noticed when i keyed the mic on 2m at 50w the solar input power would drop from 55w to zero as long as i held down the mic. redarc has confirm this shouldn't happen and is suspecting the radio is making the redarc unhappy. a fellow ham suggested some ferrite magnets on the solar input wires from the panel as well as the ground to the redarc itself. i haven't tried this yet but wanted to see if anyone had any suggestions. he also suggested i see if the problem persists on 70cm as well which i haven't tried yet.

i'm not an expert at RF by any means. looking to see if anyone has any suggestions before i go buy some ferrites from amazon to test.

thanks in advance

KK6TBF.

[W9IQ]

Before applying ferrite, you might wish to try a couple of simple 0.1 uF disk capacitors across both the solar panel input leads and the DC charge output leads. This may effectively shunt the RFI.

When dealing with DC circuits, the application of ferrite requires more attention to detail to avoid potentially saturating the ferrite and thereby rendering it ineffective as an RFI suppressant. A good practice for DC is to always wind (or pass through) both the positive and negative wires in the same core with the same number of turns.

If you do go the ferrite route, the mix of the ferrite will matter. For VHF RFI suppression, mix 43 would probably be the most effective.

 - Glenn W9IQ

[K6AER]

How far is the antenna from the charge controller and does the problem show up when the radio is on low power?