[MRCA] DC-DC Up Converter

[scottjohnson1 at cox.net]

Amazon is you friend.  There are all manner of DC-DC boost and buck converters that will do yeoman service for you,  the buck converters are a few bucks ($3-6), and there is a nice 45-390V boost converter from several sources for around $10.00. (There are two versions- a bi-polar, and a positive only, don’t get the bipolar unless you need it, as it is half the current) They will deliver up to 30W over the output voltage range.  I have used them as dynamotor replacements, literally fitting the converter in a gutted dynamotor case. I have used literally dozens of these over the last 5 years, and find they work very well, with quite high efficiency.

 

Regards,

Scott W7SVJ

 

From: mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> On Behalf Of Mark K3MSB
Sent: Friday, September 12, 2025 09:25
To: Ray Fantini <RAFANTINI at salisbury.edu>
Cc: mrca at mailman.qth.net; List Milsurplus <milsurplus at mailman.qth.net>
Subject: Re: [MRCA] DC-DC Up Converter

 

Ray and "Milrad" --

 

Thanks for the info.

My initial goal is to provide a field solution for my BC-221.  It now has a 110 VAC power supply, and I'd like to convert it to 12 V DC.

I need 6.3 V AC/DC and 150V @ 20 mA.      A single battery with the DC-DC converter should work.

I use LiFePO4 batteries for POTA (Parks On The Air) activities and can run my IC-7300 at 100W for 2 to 3 hours (which is why I typically run it at 50W).    Since the 211 will only be on intermittently, a single battery should easily last for 2 days.    

I'd generate some heat for the filament dropping resistor, but that doesn't matter.

 

73 Mark K3MSB

 

 

 

 

 

On Fri, Sep 12, 2025 at 9:21 AM Ray Fantini <RAFANTINI at salisbury.edu <mailto:RAFANTINI at salisbury.edu> > wrote:

Just finished a DAG radio direction finder using this same converter. Its providing 90 volts and replacing a B battery. Built a small box that takes the output of a twelve volt SLA Battery and provides 1.5 and 90 volts for the direction finder. Found that the inverter was fairly quiet but is almost completely lacking any output filtering. It also produced noise on the input buss to the battery but keeping everything in a meatal box and short it was not an issue. Regulation was ok but did notice there are some points where the PWM system on the board will produce weird noise at some settings. Think the little inverter is good for low power things like replacing B Batteries but would not trust it for things like 225 B+ supplies in a big radio.

 

Ray F/KA3EKH

 

 

From: mrca-bounces at mailman.qth.net <mailto:mrca-bounces at mailman.qth.net>  <mrca-bounces at mailman.qth.net <mailto:mrca-bounces at mailman.qth.net> > On Behalf Of MilRad via MRCA
Sent: Thursday, September 11, 2025 9:30 PM
To: Mark K3MSB <mark.k3msb at gmail.com <mailto:mark.k3msb at gmail.com> >; ARC5 <arc5 at mailman.qth.net <mailto:arc5 at mailman.qth.net> >; List Milsurplus <milsurplus at mailman.qth.net <mailto:milsurplus at mailman.qth.net> >; Military Radio Collectors Association (mrca at mailman.qth.net <mailto:mrca at mailman.qth.net> ) <mrca at mailman.qth.net <mailto:mrca at mailman.qth.net> >
Subject: Re: [MRCA] DC-DC Up Converter

 

 

I have had good luck with this one. 

  

https://www.amazon.com/dp/B09KRLGNH7 

On 09/11/2025 7:39 PM EDT Mark K3MSB <mark.k3msb at gmail.com <mailto:mark.k3msb at gmail.com> > wrote: 

  

  

Hi Folks 

  

A while back (perhaps a few weeks)  there was a thread on DC to DC up converters in which there was one particular unit that quite a few people liked. 

  

I thought I saved that info but didn't.  If anyone has the info, please forward. 

  

Thanks 

  

Mark K3MSB 

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