[minima] Re: Sometimes it's the simplest of things
- From: farhanbox@xxxxxxxxx
- To: minima@xxxxxxxxxxxxx
- Date: Sun, 16 Feb 2014 16:14:45 +0000
Use a 2N7000 instead?
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-----Original Message-----
From: Mark G0MGX <mark.g0mgx@xxxxxxxxx>
Sender: minima-bounce@xxxxxxxxxxxxx
Date: Sun, 16 Feb 2014 15:55:53
To: <minima@xxxxxxxxxxxxx>
Reply-To: minima@xxxxxxxxxxxxx
Subject: [minima] Re: Sometimes it's the simplest of things
Hi Andy
Thanks for the schematic; Its interesting that you have the BCD lines
tied high - however I think my problem is that I am trying to drive a
transistor/relay and one of the 4028 inputs from the same digital output.
M
On 16/02/2014 15:44, Andy wrote:
> Hi Mark
>
> I used the 4028 in a Digital VFO here so maybe you could utilise my
> switching arrangement.
>
> Regards
>
> Andy de G6LBQ
>
>
>
> On 16/02/2014 15:38, Mark G0MGX wrote:
>> Well team,
>>
>> I find myself so near but yet so far.
>>
>> I have D5 or pin 11 of the processor connected as per the schematic
>> to drive the RX LPF switch. I also have another 4K7 resistor from D5
>> to one of my 4028 inputs.
>>
>> When my D5 line goes HIGH (as the tuning passes 15MHz) my RX LPF
>> switch operates but the voltage on the 4028 is just too low to make
>> that transition. So I have tried a few alternatives including a PNP
>> transistor to switch the +5V line but that seems to be suffering the
>> same problems in that the voltage on the collector isn't doing as I
>> expect (presumably because I dont understand what I am doing).
>>
>> Can someone cleverer than I suggest how I can get my RX LPF relay and
>> my 4028 to function on the same digital output (in this case D5) from
>> Ardunio?
>>
>> Pointers and suggestions very much appreciated before I try the
>> larger of my hammers....
>>
>> Mark
>> G0MGX
>>
>>
>
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