[MRCA] DC-DC Up Converter

[Ray Fantini]

That appears to be the same DC to DC converter that’s all over eBay for between $5 and $20 they are all the same so no idea why they are priced different. My thing is that out of three of them that I played around with all had the same issues with output filtering and had to build external filter networks or at least use additional capacitors on the inputs and outputs.
The 12 volt 7.5 or 8 ampere hour SLA batteries are $20 to $30 each and in addition to this have found there way into many other projects, they make a great battery for PRC-74 transceivers and also have them in a couple of other backpack radios. We use tons of them at work for UPS systems so always have a good supply of pulls to play around with.

Ray F/KA3EKH



These on Amazon Haul appear to be the same design and are less expensive:

https://www.amazon.com/AOICRIE-Converter-%C2%B145V-390V-Capacitor-Charging/dp/B0CHF7V4ZG#haulCustomerReviews_feature_div

__... ...__ Dave N9ZC



On Fri, Sep 12, 2025, 10:40 AM <scottjohnson1 at cox.net<mailto:scottjohnson1 at cox.net>> wrote:
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<mailto:mrca-bounces at mailman.qth.net> <mrca-bounces at mailman.qth.net<mailto: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<mailto:RAFANTINI at salisbury.edu>>
Cc: mrca at mailman.qth.net<mailto:mrca at mailman.qth.net>; List Milsurplus <milsurplus at mailman.qth.net<mailto: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



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