I thought Minima begat the HF1, which then became the platform for all
such up-converting transceiver experiments.
Dale, I noticed you used "nano board driving an adafruit Si5351 LO
into a 74AC00 with -11db pad into an SBL-1 mixer" in your Minima
inspired DC receiver. I am using the same combination of Nano and
Adafruit si5351, and an unsure what to do about cleaning up the
harmonics on the square wave output before the SBL-1 mixer. I asked
this question on qrp-tech list a month ago.
Are you using the NAND gates as a squarer, to eliminate harmonics? If
so, did you try conventional LPFs? And clearly you don't mind driving
the SBL-1 with a square wave. What is the highest frequency your
74AC00 works at? Any further things I should know before trying this?
regards Paul VK3HN.
On 18 February 2017 at 22:37, Dale Ward <adwsail@xxxxxxxxx> wrote:
A failure? Imho certainly not. And not because the Minima as designed was a
'wire it up as shown and go' but because of the motivation it provided. I
went with a D.C. Receiver loosely based on W7EL's optimized Transceiver. In
my version I used a nano board driving an adafruit Si5351 LO into a 74AC00
with -11db pad into an SBL-1 mixer. That was followed by a diplexer and LNA
into 2 sections of NE5532 for audio gain into a tiny class D amp to drive a
speaker. Stunning performance and over a years worth of learning to get it
all working. The modular approach with careful 50 ohm matching of each
section made it simple to try countless iterations of oscillator, passive
filters, audio high gain stages, etc. and, at least for me, my deepest
thanks to Farhan for his inspiration.
The only true failure comes from not even trying.
