[ARC5] restoring hacked vhf receiver

[Bob kb8tq]

Hi

Most of what you see runs a square wave at 20 to 60 KHz. Without added filtering
on both the input and the output you *will* see RFI out of them. They also require 
some amount of air flow to cool them. If you are putting out 30W, you should count 
on getting rid of 6W or so. The cooler you keep them, the longer they will last ….

All that said, they are a good way to get the job done. You can’t build something 
better for the same money. 

Bob

> On Mar 6, 2018, at 12:16 PM, David Stinson <arc5 at ix.netcom.com> wrote:
> 
>  
>  
> From: Robert Eleazer
> 
> Subject: [ARC5] restoring hacked vhf receiver
>  
> By the way, I am wondering about those buck-boost converters you see for sale for a few bucks the ones that can take in around 5 to 30VDC and put out 1.5 V to 35 VDC.  I have been trying to build am LM350 circuit to provide a little over an amp at 28 VDC to power a radio and while it worked at first it's been driving me nuts.  Is the power out of those buck/boost converters fairly clean or are there lots of harmonics?
>  -----------------------
>  
> They are very useful, and they are very RF-noisy.  One really needs to build it into an RF-tight enclosure with filtering in and out.  I posted about this a few days ago.
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