RFI
[Top] [All Lists]

Re: [RFI] SO2R 2nd Harmonic Interference

To: Grant Saviers <grants2@pacbell.net>
Subject: Re: [RFI] SO2R 2nd Harmonic Interference
From: myles Landstein <myles.landstein@gmail.com>
Date: Sat, 29 Sep 2018 18:28:23 -0400
List-post: <mailto:rfi@contesting.com>
yup  the battery tender unit’s throw out a lot of  RFI for sure and have also 
noticed moderate life spans on there switchers. However Their transformer unit  
 is rfi quiet and lasts a long time.

never tried the  battery minder units.





myles Landstein
myles.landstein@gmail.com



> On Sep 29, 2018, at 6:22 PM, Grant Saviers <grants2@pacbell.net> wrote:
> 
> I have found the "Battery Minder" products quiet and reliable. Not to be 
> confused with Battery Tender which have had a high failure rate for me.  The 
> Minder brand uses a pulse charge float technology and has recovered partially 
> sulfated batteries for me and has the lowest water loss of any float charger 
> I have used.
> 
> Two are on 24x7 24v 2 to 4a outside (48v x 220AH), one 12v 1a outside on 24x7 
> (12v x100AH), and one inside 12v 2a on 24x7 (12v x 220AH).  I haven't added 
> chokes on any of them.
> 
> Not cheap but worth it as batteries really last and are always ready to go.
> 
> Grant KZ1W
> 
> On 9/29/2018 13:52 PM, Randall K Martin wrote:
>> I have been trying to solve an interference problem for quite a while here 
>> at my QTH. Symptom is that when I transmit on 40M CW, even at QRP power 
>> levels using bandpass filters and transmitting stubs, the second harmonic on 
>> 20M is a wide signal, covering 30-40 KHz. As per advice given by Frank W3LPL 
>> regarding RF flooding, I started searching for an electrical device 
>> (probably charger/wall wart).
>> 
>> I eliminated my own home as the source by testing with battery power and all 
>> circuit breakers turned off. Through more testing, I found that even at 100 
>> milliwatt output on 40M, I still got the 20M wide band hash, but only when I 
>> pointed my 40M antenna at my neighbors house.
>> 
>> Today, I got together with the neighbor and he let me snoop around with a 
>> portable Rx. Voila! Culprit is a cheap little trickle charger.
>> 
>> DBT Auto Electrical Products PTE LTD Part no. 021-0123
>> "Household automotive battery charger" 120V input and 12V output at 750 mA
>> 
>> Question: Is there a battery charger that any of you can recommend? I tried 
>> wrapping the 12V leads of the current charger roughly 10 x through a large 
>> toroid and there was little if any reduction in interference.
>> 
>> 73 Randy K0EU
>> 
>> 
>> 
>> _______________________________________________
>> RFI mailing list
>> RFI@contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>> 
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi

_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
<Prev in Thread] Current Thread [Next in Thread>