CLOSED - MAX-BR1_Mini-LTE-US-T Reboots whenI transmit HF (Amatuer Radio Operator)


#1

GReetings, I have a MAX-BR1_Mini-LTE-US-T that reboots when I key up my HF radio. Max power on Radio is 100w. Ham radio antenna and feed line is at 1.2:1 SWR. No other device in house is effected by the HF transmitted signal. Happens in 75 meter band (3,8mhz), and in MARS bans slightly higher frequency between 4-5 mhz. Moved PepWave router around various places with same effect. PepWave even reboots with cellular and WiFi antennas disconnected. Also installed a RF choke for HF frequencies - still reboots. I have no requirement for GPS since I always know where my house is, antenna so it’s never connected.

I looked for an external ground but the PepWave unit does not have a grounding terminal.

My Cisco router, Cisco switches and Cradlepoint router are not effected when I transmit RF. No other electronic devices in my house are impacted. My neighbors do not report any impact. Any ideas/suggestions would be greatly appreciated.


#2

Hi Stel,

May I know where did you install the RF choke?


#3

I installed the choke on the DC power line form the wal-wart by wrapping the DC plug around the choke, about 6 turns. This attempt was a donut style choke used by ham radio operators to block HF current. I also tried a clamp-on style. Tried both chokes at the wal-wart and DC plug ends of the power cable. No impact.

Also, moved the PepWave out of the radio room to the 1st floor of the house furthest away from the antenna tower. Antenna is a 420 ft square loop.

I am baffled. Don’t have an RF field strength meter. Wait a second… Maybe I do. Will report back if my antenna analyzer has that feature.

EDITED: MY Antenna Analyzer does not have a field strength feature… https://www.mfjenterprises.com/Product.php?productid=MFJ-269C

Hope this gives more detail. Thanks!
John


#4

Hi John. That’s the first place I would have choked also. You’re using the correct mix, right? Probably 43 or 61? Have you taken a look at K9YC’s “cookbook?” http://www.audiosystemsgroup.com/RFI-Ham.pdf

Jees, does not seem like you should have to build a Faraday cage for it! :wink: But maybe …

I’ll pass one one experience which may or may not be of help … Not long ago I had a problem with a CCTV NVR. The NVR got really whacky when the vertical antenna about 80’ away came on line with 1.5KW or so – worse on RTTY than SSB or CW, as expected. The solution was to choke both the RG6 analog inputs and the Ethernet cables. I then removed them one by one until the problem reappeared. Bottom line was that it was one long RG6 run and a long Ethernet cable. “Side note” regarding the latter: In such environments we have long abandoned plain ol’ cat 5 cables and moved to either shielded Cat 5E or Cat 6.

Please keep us informed as to your progress!

Rick


#5

CLOSED (sort of solved). I ran a ground of 16ga stranded copper wire from the external antenna (cellular primary) to house ground using a spade lug at the outlet and twisted the stranded wire around the gold plated antenna SMA connector. Length of ground wire is shorter than the DC wall wart power cable, 3 ft ±. Not soldered but twisted tight. Made several transmissions on HF with no negative impact on router. Seems like there should be a ground incorporated in the design but I understand this router was meant for mobile use. We can consider this issue closed.
John
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