Hi Joe,
Acedamic or not, i thank you for your input. Designing anything meaning making
a lot of compromises, and it start with knowing all the pro's and con's.
A PCB using AND the handmade mixer AND the prefab one taking more realestate on
the PCB thaN less, and the idea was getting the PCB smaller.
Using 3 coax wires to land the mixer signal does make the PCB a lot smaller,
but it shifts the problem to another PCB. Additional we create a new problem as
coax lines are prone to problems, like broken inner cores and ground shortages,
but, if this is the choosen solution, it solves the size problems.
If we will use prefab amplifiers with SM devices, made by a special taskforce,
nobody would need to touch the SM devices. The main PCB would be using 400V
capacitors, Xtals and 6mm coils, but there are almost no places for SM left, so
this cannot be a problem.
And about the si5351, if somebody would find a solution for the crosstalk, it
would solve the adressing problems on the bus.
Regards Ben PA9B (in Turkije)
-------- Origineel bericht --------
Van:Joe Rocci <joe@xxxxxxxxxx>
Verzonden:Wed, 01 Jun 2016 20:09:05 +0300
Aan:minima@xxxxxxxxxxxxx
Onderwerp:[minima] Re: looking for HF1
Ben
I’m not currently building this, so my thoughts might be somewhat academic.
However, I suggest drawing the schematic and laying out the main board so both
options are available; ie, packaged mixer vs discrete mixer and on-board xtal
oscillator vs Sixxxx. Here, Sixxxx means Si570 or Si5351, whichever is
preferred. The ‘5351 has the advantage of 3 oscillators in one package and the
disadvantage of numerous crosstalk spurious and higher phase noise. However,
if you just provide inputs for external synthesizers, this could be an
external board option. I’m personally fine (actually happy) with SMD parts,
but I think the broader population of builders would prefer leaded components.
Joe
W3JDR
From: Ben Aupperlee
Sent: Wednesday, June 01, 2016 12:37 PM
To: minima@xxxxxxxxxxxxx
Subject: [minima] Re: looking for HF1
Hello Ashhar,
I have redrawn the analog part of the schematic of the HF1 (using paint.exe),
and as there was a very clear and strict copy right notice, i am sending you
this drawing so you could see your own text and answere two questions, first
what is that diode on top of amp 1 doing there, and second, L9, I presume it
to be around 250 to 300nH.
Furthere, there is a discussion about some changes in the population of the
board, here my point of view in temp.HTM
REGARDS Ben PA9B (in Turkije)
