Hit the return button on that one a little too fast, sorry.
Anyway, I'm hoping you can shed some light on the antenna input numbers...whether you think the variance could be the problem, or is it something else I should be looking at?
I'm assuming that since I am only using a mono input computer (my laptop) that the other un-monitored output can't be part of the problem.
Since I'm getting identical output levels from the 2 units with no antenna attached, I am assuming the problem is not with the I or Q audio output IC.
Should I be looking at the input circuit as the likely cause of the problem? I did drop the toroid (hard tile floor), so there might have been some damage done to it...but it's not visible and those units are pretty rugged. I looked it over well with the magnified desk lamp, and it did not appear to have any cracks in it.
I did confirm the inductors (L1 and L2) were placed properly (by measuring them with my RCL meter), so they are probably not installed int he wrong PCB locations.
Any suggestions??
Art
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At 04:06 PM 10/8/2005, you wrote:
Hi Art,
Not sure I understand your table of data. However, I would be happy to give
you a telepone call and see if we can track down the problem with your
SoftRock. I have worked with a number of others over the phone and I think
it has helped them a bit. If you would be interested in doing that, send me
an e-mail at raparks@... with your telephone number and what time I
should call.
73,
Tony KB9YIG
----- Original Message -----
From: "KY1K" <ky1k@...>
To: <softrock40@...>
Sent: Saturday, October 08, 2005 2:23 PM
Subject: [softrock40] ANTENNA INPUT CHARACTERIZATION
Greetings all,
As previously reported, my softrock is dead-has to be a bone
crushing+ loud signal to be heard. But, the output level to the sound
card appears identical compared with my borrowed and fully functional
softrock. By this I mean that both units put out the same signal
level to the soundcard with no antenna connected....in fact, it's
impossible to tell them apart until a decent antenna is connected.
So, I figured I had a tuned circuit problem between the antenna and
the transformer...but that the power supply, the switch and the logic
was probably working fine.
I borrowed an MFJ antenna analyzer (MFJ-269) and fed the thing into
the antenna input.
I've checked these figures twice, got the same numbers both times.
These measurements were taken on the bench with power applied from
the computer and with the connection made to the sound
card (without antenna attached). I have a fairly high degree of
confidence that the MFJ is in working order, it's used often and has
recently made stubs for 6 meters and the numbers seem reasonable when
hooked up to my 2 meter yagi.
So, here is are the results.
SWR
Rs Xs
5 Mhz 15(12) 12(15) 102(96)
6 Mhz 1.7(3.2) 77(14) 26(12)
7 Mhz 3.8(2.1) 30(24) 63(12)
8 Mhz 2.7(2.4) 113(21) 56(14)
9 Mhz 1.0(5.3) 49(11) 2(25)
Has anyone else had their softrocks hooked up to an antenna analyzer?
The numbers seem like they should be a little closer to each other,
so I'm not sure whether to look at the tuned circuit or elsewhere.
Any suggestions?
HELP!!!!!!
Art
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