Re: QSX radio feature requests



I had the Altair "binary blisters" for several years, so I know what you mean. One of my favorite T-shirts say:

    There are 10 kinds of people in the world:
        Those who know binary and
        those who don't.

Jack, W8TEE

On Saturday, August 25, 2018, 11:43:49 AM EDT, Arv Evans <arvid.evans@...> wrote:


My comment was more about being familiar with binary progression than about
actually writing code.    8-)

Guess I'm showing my age if I admit that my first computer was a sales sample
8008 from Intel and it did boot to a paper-tape drive by entering the boot sequence
with toggle switches.  We have come a long way since then.


On Sat, Aug 25, 2018 at 9:25 AM jjpurdum via Groups.Io <> wrote:

Why machine code? Why not use C?

Jack, W8TEE

On Saturday, August 25, 2018, 11:22:29 AM EDT, Arv Evans <arvid.evans@...> wrote:


My own QRP ATU uses binary progression of inductances with a 0-150 pf
variable cap and a switch for adding another 150 pf fixed C.  It doesn't seem
to be too much of a stretch to have the C values also binary progression. 
Might take a bit of thought for those not used to programming in machine
code but it does seem doable. 

I'm curious about how small latching relays work.  My only experience in
that area is with much larger units.  They had two coils, one to operate the relay
and another to release the lock.  Do the small ones work that way. or is
there some other methodology?  Magnetic latch?


On Fri, Aug 24, 2018 at 8:17 PM J68HZ <bill@...> wrote:

Woah, wait.  Toggle switches to replace the relays???!!!!  So how do you propose that would work… do a binary search towards a low SWR solution?  That reminds me of loading the operating system into an ATARI 8080 system using front panel switches…  could take forever and a few days.  If you are worried about current draw, go with latching relays.  Back in March, I bought several hundred latching relays for $0.89 each… yes they can be had cheap if you buy them right from the source.



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From: [] On Behalf Of Arv Evans
Sent: Friday, August 24, 2018 8:18 PM
Subject: Re: [QRPLabs] QSX radio feature requests



The K3NG ATU is an interesting design but uses several relays.  That is fine for automation

purposes, but I wonder if the design could be reproduced with a handful of DPDT rocker or

toggle switches replacing the relays.  Maybe there needs to be 2 versions of this well thought

out design, one that is automated and another that is manual for low current draw and increased

battery life for portable use.



On Fri, Aug 24, 2018 at 6:27 PM Glenn <glennp@...> wrote:

The K3NG ATU lends itself to home brew.   And changes to the power level required. My own build I estimate at around 20-30W and uses smd 2-3kV caps (overkill) and the usual relay switching of L&C. Two relays are used to switch the ends for L-C or C-L. I used standard relays, not latching, due to cost here in VK. Control board uses a NANO with a 0.96" OLED display.



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