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<p>Dave,</p>
<p>Thanks for the post! I would recommend that you change the title
of your description from "ANAN-10 as a Transverter Driver" to
something else, because you didn't use an ANAN-10 in your tests.
You used a TAPR Hermes card and an ANAN PA module. While the
results might well be similar to what would be seen with an
ANAN-10, labeling your test results as coming from an ANAN-10 [and
thus from Apache] is incorrect, and I think unfair to Abhi and
Apache. Your post, to which this is a response, also incorrectly
identified the hardware that you tested as an ANAN-10.<br>
</p>
<p>I think it would have been acceptable and fair to surmise in a
conclusion to your online article that the results might apply to
an ANAN-10, as long as the title and lead-in to the article didn't
imply that it WAS an APACHE-made ANAN-10 that you were testing
when in fact it was not.<br>
</p>
<p>I have not worried here about harmonics from my multiple Hermes
[and Atlas] units here, because the input filtering in my
transverters eliminates the need for such concern. But I agree
that if someone had a transverter with a 28 MHz IF that had an
input passband including up to 56 MHz or even 84 MHz, then the
harmonics would be a concern and an additional LPF would be
necessary, as you rightly pointed out in your test of your TAPR
Hermes card as described at the URL you posted.<br>
</p>
<p>I asked Abhi about his thoughts on the concerns expressed in this
thread, and as always I got a quick, helpful, and carefully
considered response. Here is what he sent me:</p>
<p>1. The Hermes card on it's own is not intended to be used as a
transmitter since it does not provide either LPFs or a T/R switch,
when used at around 300mw or lower the harmonics on all HF bands
will be around -30dB except on 6M where they are lower due to a 6M
LPF which is on the Hermes Tx path, hence Hermes stand alone does
not meet FCC requirements nor was it intended to on it's own,<br>
<br>
2. When using a transverter @ 28Mhz with Hermes it is expected
that the transverter will have a 10M BPF to eliminate the
harmonics before mixing with the upconverter, the final
Transverter PA will also have an LPF.<br>
<br>
3. There is a low noise SMPS which converts 12v to 5v onboard,
although well designed by Kjell, LA2NI expecting it to have no EMI
radiation is trying to defeat the laws of physics , however, the
SMPS switching frequency harmonics are very low and in no way
effects the transmitted spectral purity.<br>
<br>
4. The ANAN-10 PA has a bank of seven LPFs covering 160M through
6M, Hermes when used with the 10W ANAN PA meets and exeeds FCC
requirements.<br>
<br>
The user is seeing spurii a few hundred Khz above and below the
fundamental, these are possibly generated by the Hermes card, he
should in fact update the board firmware and reset the PowerSDR
Mrx database to see if that resolves the issue if not the Hermes
board he is using may require service, The spurii he is seeing are
definitely not generated by the PA.<br>
</p>
-----------------------------------end of comments from
Abhi---------------------------------------<br>
<br>
I've always found Abhi and Apache to be the "Best of the Best" when
it comes to solving problems, answering questions, etc. My
experience here has always been that he goes beyond what would be
expected even from the "Best of the Best" when potential issues or
questions arise. <br>
<br>
I am following this thread with interest, as I have several TAPR
Hermes cards. But I still call them Hermes cards, even though I
have housed them in Apache ANAN-10 boxes :)<br>
<p>73,</p>
<p>Roger W3SZ<br>
</p>
<div class="moz-cite-prefix">On 8/5/2016 12:45 PM, Dave wrote:<br>
</div>
<blockquote cite="mid:001801d1ef38$c858b9c0$590a2d40$@com"
type="cite">
<pre wrap="">***** High Performance Software Defined Radio Discussion List *****
Hi Dom
I saw nothing within -70dBC inband on my ANAN10 when using the xverter port
on 28MHz . My Anan has been used on many 2/4m contests with a Transverter
without complaints from my (VERY) locals
This port does however have bad harmonics see
<a class="moz-txt-link-freetext" href="http://g4fre.blogspot.co.uk/2013/11/anan-10-as-transverter-driver.html">http://g4fre.blogspot.co.uk/2013/11/anan-10-as-transverter-driver.html</a>
Dave
G4FRE
-----Original Message-----
From: Hpsdr [<a class="moz-txt-link-freetext" href="mailto:hpsdr-bounces@lists.openhpsdr.org">mailto:hpsdr-bounces@lists.openhpsdr.org</a>] On Behalf Of
Dominique Dehays
Sent: 05 August 2016 17:31
To: <a class="moz-txt-link-abbreviated" href="mailto:hpsdr@lists.openhpsdr.org">hpsdr@lists.openhpsdr.org</a>
Subject: [hpsdr] ANAN 10 28Mhz tx spectrum and generated birdie
***** High Performance Software Defined Radio Discussion List *****
Hello ,
after getting a local friend complaining about hearing me on several
frequencies , I've measured the anan 10 output spectrum , and was
surprised to find spuriis 295 and 590 Khz each side of the carrier at
-60db/-63dB. I know it is within FCC norms but it is really annoying.
Another problem is that the anan generates a wide drifting birdie in my
144Mhz receiver ( of course a separate receiver not the anan). Anyone
got the same problems?
73
Dom
_______________________________________________
HPSDR Discussion List
</pre>
</blockquote>
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