SailNet Community - View Single Post - VHF Output
Thread: VHF Output
View Single Post
post #11 of Old 10-24-2012
Join Date: Apr 2006
Posts: 12,474
Thanks: 7
Thanked 189 Times in 185 Posts
Rep Power: 13
Re: VHF Output

"Buck converters (step-down), boost converters (step-up) and buck/boost converters (anything to anything) aren't special. They're in almost every electronic device over a few watts.... on the oder of $15 in lowish quantities."
Actually, not. First of all, dcd-dc converters of any type are not used in anything like a mass or majority of consumer electronics. Bulk regulators, when needed. But anything more? No, not without a real need. You go add $15 worth of components, or even $5 worth of components, to a VHF that is designed to sell for $100-150. You'll bump the retail price by $20-30 and lose market share, that's the reality of the mass market. If you can knock one buck, one dime, off each board? That's sometimes the difference between success and bankruptcy. That's just the way it is. And there are engineers who are hired specifically to say "OK, we've got this, what can we knock out of it?" including electronic components.
What you would like, has been proven impossible in the mass market. In a $500 VHF, sure, you could expect that. And we could all buy bespoke suits instead of khakis. Ain't gonna happen.

"A cheap incandescent flashlight won't have regulation but a good LED one will." Not really. Many LED flashlights have no regulation, they rely on the battery voltage being the limit and don't regulate anything. SOME use upconverters, in order to get a 4.5V white LED running off a single AA cell, but that's because it has to be done that way--not because someone wanted to spend the money doing it. Others use *power* regulators, simply because using a power regulator on a $10 prime LED can double the operating life, and some folks will pay for that. Again, it is not mass market. Like a Bose stereo, they ay sell a lot of them, but it is not mass market.

"but being able to put out 25W on your VHF at 11.5V in a boat is a pretty damn good reason for regulation. " Not really. If all you can supply is 11.5 volts, the "operator" has already failed to maintain their nominal power supply. That's user error, failure, and not common operating mode. In order to make that happen with an ordinary regulator, you'd have to design the whole radio to work at 10.5v,not 11.5, then add a regulator which only had a one-volt power drop in it. Oh yes, all regulators consume power and further reduce source voltage, until you get into dc-dc converters and then again you drive the costs up AND you create RFI in the radio itself, which makes a bad thing even worse.

You think you can do a DC-DC regulator to make your VHF happy with 11.5 volts for under $15? Great, wire it up, hook it on! But the industry has good reasons for not doing it, starting with that HUGE $15 extra cost, from their point of view.

Sure, there are all sorts of new poewr supply chips on the market now. They still cost money. They still need engineering expenses. They still need HEAT SINKS which means more space and more money again. You're not going to do the job with a 2mm x 2mm chip.

And coming back to the most important point of all: 99% of the buyers have no need for it, no understanding or appreciation for it, and no budget for it. Did I mention, "Ain't gonna happen." ?

For those buyers who want better emergency operation, buying a $20 dedicated VHF battery and mounting it behind the radio will do very nicely. It will buy you more protection that any regulation of the vulnerable ship's power system.

But coming back full circle, if you've tested two radios and both put out the (curiously same) 15W of power...I'd look to what you are feeding them. Especially since both are being degraded to the same power level, indicating that's all the power they can find on the DC line. tell me how easy it is to improve the electronics--when the way simpler problem of wiring is still apparently in the way?

First fix it. Then worry about whether it needs to be improved.
hellosailor is offline  
Quote Share with Facebook
For the best viewing experience please update your browser to Google Chrome