[minima] Re: A (temporary) solution to my mixer problems
- From: Mvs Sarma <mvssarma@xxxxxxxxx>
- To: minima@xxxxxxxxxxxxx
- Date: Wed, 22 Oct 2014 23:32:07 +0530
hi Dan,
IMHO , is conventional to call T or Pi attenuator *a pad*.(three
resistors forming a T attenuator or pi attenuator.)
On Wed, Oct 22, 2014 at 11:16 PM, Dan Reynolds <on30ng@xxxxxxxxx> wrote:
> Wayne, for us dummies can you show us what the pad looks like - schematic.
> Just need a brain check.
>
>
> 73
> Dan -- KB9JLO
> https://sites.google.com/site/on30ng/
>
> On Wed, Oct 22, 2014 at 12:05 PM, Wayne McFee <nb6m@xxxxxxx> wrote:
>
>> Thomas,
>>
>> I'm into a second build of the Minima and am using an ADE-1 as the first
>> mixer as well.
>>
>> Since the Si570 output is some +13 dBm, and the ADE-1 needs only +7dBm LO
>> drive, I placed a 50 Ohm resistive pad in line to reduce it down to that
>> level.
>>
>> If you haven't yet done that, you should as that will help reduce
>> spurious responses from the mixer and should reduce LO leakage on transmit
>> as well.
>>
>> I have just the receive portion built so far, so cannot yet give you ye
>> figures from mine.
>>
>> 73,
>>
>> Wayne NB6M
>>
>>
>> > On Oct 21, 2014, at 9:42 PM, Thomas Sarlandie <thomas@xxxxxxxxxxxxx>
>> wrote:
>> >
>> > Gang,
>> >
>> > After looking at the RF386 this afternoon I came to the conclusion that
>> my only problem was my Minima. With -30 dBm on the output my signal was
>> just too low, even for the RF386.
>> >
>> > I looked into the recent discussions about mixers and wanted to build
>> one of them but I do not have the IC you discussed and I could not find a
>> clear call on which one of the JFET mixers was the best.
>> >
>> > So I took a step back and realized that (to me) this project is more
>> about building a working radio than running lots of mixers experiment. I
>> completely removed the KISS mixer from my Minima and replaced it with one
>> of the ADE-1 mixer that I had ordered a few months ago.
>> >
>> > My output is now at -15dBm @14.250 and -26@34.25.
>> >
>> > <dsa 201410211956.png>
>> >
>> > I should now have plenty enough power to drive the RF386!
>> >
>> > I think we should recommend this solution to new builders who are just
>> getting started, at least until we have a good mixer that can easily and
>> repeatability be built with good performance.
>> >
>> > I paid $15 for 4 of them on eBay. $3.5 a piece.
>> >
>> > Thoughts?
>> >
>> > 73,
>> > thomas
>>
>>
>
--
Regards
Sarma
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