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Hi Genadi
I tested AD831 mixer in my receiver. In my opinion this mixer is much better then passive mixer ADE-1. I use this mixer in my SA in 2-IF. AD831 is very sensitive on LO level. To much LO level increase distortion products. To low LO level decrease conversion loss and IP3.
15-05-2012, 9:56 (Ten post był ostatnio modyfikowany: 15-05-2012, 9:56 przez UA1ARN.)
New RX schemaics with ADE-1 as 1-st mixer and AD831 as second mixer. If p-cad 2002 files acceptable, I can upload these files.
Source files of control program for TRX based on this RX board placed here: http://www.cqham.ru/forum/showthread.php?t=9688
Project configuration named CTLSTYLE_V8A should be selected in file product.h.
По русски приёмник называется "Воронёнок" - "little crow".
15-05-2012, 21:06 (Ten post był ostatnio modyfikowany: 15-05-2012, 21:12 przez UA1ARN.)
(13-05-2012, 18:41)SQ4AVS napisał(a): tego układu nie da się porównać do ne602 bo biję go na głowę ;-)
jeszcze jeden trx na nim
z Kolegów w SP trx na tym scalaku przerobiony DC7 ma SP7OGR
AD831 TRX dl4jal.PDF
Bay the way, i'm looks into attached .pdf and not found any matching circuits at RF input of AD831. I'm use wideband transformer ADT16-6T in old design radio (1:16 == 50:800 OHm matching) for achieve best RF sensetivity.
(14-05-2012, 17:32)SQ4AVS napisał(a): Hi Genadi
I tested AD831 mixer in my receiver. In my opinion this mixer is much better then passive mixer ADE-1. I use this mixer in my SA in 2-IF. AD831 is very sensitive on LO level. To much LO level increase distortion products. To low LO level decrease conversion loss and IP3.
If optimum is a highest dynamic range - ADE-1 (TUF-1) is a preferrable device (rather AD831). I'm already test this chip and move in position after roofing filter.
Also, sparks eaesy destroy AD831 at input stage.
17-05-2012, 17:56 (Ten post był ostatnio modyfikowany: 17-05-2012, 19:30 przez SQ4AVS.)
Ad 1 It isn't my schematic only Dl4JAL. I use matching circuit.
Ad 2 In my opinion preferable mixer is AD831. ADE-1 has IP3 +15dBm, AD831 +24dBm but for optimum performance you must set correct LO level. This is very important.
17-05-2012, 18:20 (Ten post był ostatnio modyfikowany: 17-05-2012, 18:20 przez UA1ARN.)
sounds good... but: look TPC 9 on page 5 in .pdf: I'm use same output schematics - with output transformer 4:1.
These parameters (IP3) in AD document referred to output = IP3o. Gain of this chip near to 20 dB with properly matched input...
About LO level: i'm use -3..0 dBm source with 1:8 transformer at LO input. I'ts enough for AD831?
ps: in russian forums i'm place tagline "Я там глубину сам промерял!". I mean: "Byłem tam zmierzył głębokość!"
17-05-2012, 19:15 (Ten post był ostatnio modyfikowany: 17-05-2012, 19:32 przez SQ4AVS.)
See TPC1 ;-) I measure IP3 too. I have two signal generator ;-)
You wrote: LO level -3dB to 0 dBm -is to big. When you have output transformer you must multiply voltage by sqrt(8) for example 0,224V (0dBm) after multiply is 0,63V. AD831 is sensitive on input voltage. When you have typical -10dBm (figure 9) it's only 0,07V. Please send me your e-mail. My email is sq4avs(at)gmail.com
