2018 QST Review ANAN-8000DLE

DL5RBW
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2018 QST Review ANAN-8000DLE

Postby DL5RBW » Tue Jun 18, 2019 7:59 pm

I just stumbled across a review of the ANAN-8000DLE in the April issue of the 2018 QST and was surprised about the 3rd order TX IM figures (@ 200 W output) listed there. The review can be found by clicking on the following link scrolling to the bottom and then click on "ANAN 8000DLE product review" just below the Summary.

http://radioaficion.com/cms/anan-8000dle-review/

As mentioned above the product review dates to April 2018 and maybe something has changed meanwhile however the datasheet of the ANAN-8000DLE on the APACHE LABS homepage was around at that time already and claiming up to -72 dB for 3rd order TX IM (@ 200 W output on 20 m).

???
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w-u-2-o
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Re: 2018 QST Review ANAN-8000DLE

Postby w-u-2-o » Wed Jun 19, 2019 1:12 am

The performance claimed by the Apache web site does not match up with anyone's real world performance that I'm aware of. That said, when this review came out it was obvious to everyone that the testers clearly either did not know what they were doing with PureSignal or that the unit was broken in some way. Normal 3rd order IMD with PureSignal on is certainly in excess of -50dBc. With PureSignal off the numbers look good.

73,

Scott
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Re: 2018 QST Review ANAN-8000DLE

Postby K9RX » Wed Jun 19, 2019 12:43 pm

Just as a note re this subject: there was a follow up article which stated they sent the unit in to Doug and he found some caps that were wrong ... I believe that was it - and they retested and had good results with the change made... of course the main article had already done its damage - no fault of ARRL though since it was indeed a rig issue...

Gary
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DL5RBW
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Re: 2018 QST Review ANAN-8000DLE

Postby DL5RBW » Thu Jun 20, 2019 7:34 am

I expected there must have been a follow up or a rebuttal but not being a subscriber of QST I only could search the internet and couldn´t find one there - thanks for the info on that.

Regarding the review I don´t think it was obvious to everyone that something went wrong because otherwise the review based on an obvious defective rig wouldn´t have been published with these figures. Of course people that are familiar with the effect of PureSignal and especially people who have used this feature had their doubts about the test results. However the -72 dB claimed for 3rd order IMD (TX) in the datasheet have never been seen here with a spectrum analyzer. It is more in the -50 dB region as mentioned which is still a superb value.
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Re: 2018 QST Review ANAN-8000DLE

Postby K9RX » Thu Jun 20, 2019 3:28 pm

I see -60 a good bit of the time ... I've seen as good as -65. Probably band dependent (mostly due to the contributions of the amp more than likely) ... but generally it is around -60.

Gary
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WA0VY
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Re: 2018 QST Review ANAN-8000DLE

Postby WA0VY » Thu Jun 20, 2019 11:23 pm

I'm sorry, I'm not willing to let QST, or the author, off for making such a clear error. Whether the problem was in the hardware or otherwise, it does not excuse the fact that something was obviously wrong with their data. These reviews are important and must be credible. They should have double checked before they published.
73 Brent WA0VY
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Re: 2018 QST Review ANAN-8000DLE

Postby K9RX » Fri Jun 21, 2019 1:32 pm

Brent,

If you're saying the results were not indicative of the claims I'd agree... but they in fact DID report the results THEY got. Would I have preferred at that time they request info/help from Apache Labs - yes and maybe. To just let it lie there is a bit of a disservice - but you have to remember - they are testing rigs bought anonymously - and they assume, right or wrong, that those rigs are a representative sample of what is available. I don't know that they can be blamed for getting a bad rig. If they were asked or expected to always question 'bad' results they'd have ALL reviews held up for some length of time ... some of the rigs out there are VERY poor performers .... I don't know that it is their job to do that - they test a rig - they report the results. If the rigs meet the specs published reliably - there should be no issue, correct? In this case it didn't.

I think the one thing I'd ask them to do is to put a note, when there is an irregularity, that says "this does not meet the manufacturers published specs/stated results, we've submitted these results to the manufacturer for comment"... or some such statement so the reader is aware of a potential issue with THAT rig.


Gary
DL5RBW
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Re: 2018 QST Review ANAN-8000DLE

Postby DL5RBW » Mon Jun 24, 2019 7:10 pm

Agree - I would have expected that the people responsible for the test results at least contact the manufacturer BEFORE publishing the results if the measured results are that far off from the specifications published by the manufacturer. At least this is what happened in the past with products from other manufacturers. The result in this first review is so far off from what is experienced by other owners that the first tested unit is for sure not representative. For 3rd order TX IMD being down 30 db or less it would not be necessary to introduce a complex algorithm. It is surprising that this has been completely overseen (one could say ignored) by the last instance, the editor. At least this chain operation is the usual process to have as many “fuses” as possible to avoid mistakes like this.
DL5RBW
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Re: 2018 QST Review ANAN-8000DLE

Postby DL5RBW » Mon Jun 24, 2019 7:11 pm

Gary,

how did or how do you run the IM test on your ANAN-8000? Do you use the internal 2-tone test generator with Duplex function and peak hold?
K9RX
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Re: 2018 QST Review ANAN-8000DLE

Postby K9RX » Tue Jun 25, 2019 1:33 pm

yes - although I don't think I have "peak hold" .... I don't remember a peak hold. NOTE however I routinely see -60 when using it on SSB. I have my TX monitor display set to +10 and -70 and that allows me to see the start of the shoulders at ~-60 and the peak is at the top of the 'grid structure' at +0.

Gary
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Re: 2018 QST Review ANAN-8000DLE

Postby DL5RBW » Wed Jun 26, 2019 8:37 pm

O.k. - I see the same numbers here while using the ANAN in Duplex mode. However I did some measurements with an external spectrum analyzer and see TX 3rd order IMD about 50 to 60 dB down (band dependent) with both methods as long as I run the ANAN-8000 barefoot and the jumper on the back of the radio set. The same is true with my external coupler that is behind the amplifier. As soon as I switch the amplifier online and using the external coupler to include the amplifier in the predistortion loop 3rd order IMD still is 50 to 60 dB on the ANAN but the external spectrum analyzer shows 40 to 45 dB. The 40 to 45 dB have been confirmed by a local ham with an SDR. The external spectrum analyzer is not overdriven but still has enough dynamic to determine that the results are not as good as shown on the ANAN-8000. I keep the power level on the ANAN low enough to make sure I don´t get a powersupply overload issue.

ANAN-8000 barefoot with integrated coupler -50 to -60 dB (measured with the ANANin Duplex & Peak mode, external Spectrumanalyzer and local SDR)
ANAN-8000 barefoot with external coupler -50 to - 60 dB (measured with ANAN in Duplex & Peak mode, external Spectrumanalyzer and local SDR)

ANAN-8000 with amplifier and external coupler -50 to -60 dB (measured with the ANAN in Duplex & Peak mode)
ANAN-8000 with amplifer and external coupler -40 to -45 dB (measured with the external Spectrum analyzer and local SDR)

What is strange is that both the spectrum analyzer and the local SDR give the same results while the ANAN seem to "lock" it to the -50 or -60 dB value but it is simply another local SDR too. The values on the ANAN become worse when going from TX to RX (peak hold mode). If you stay on TX the values are better by approx. 10 dB on the ANAN. I assume this has to do with the automatic attenuator changing the setting when going from TX to RX. The linearity display doesn´t show any sign of memory effects on both amplifiers (amp 1 is an ALPHA77SX while amp 2 is a homemade tetrode amplifier). I get the same -40 to -45 dB of 3rd order IMD with the amplifiers out of the predistortion loop by just using predistortion on the ANAN and using the clean signal to drive the amplifiers.

I need to perform more measurements to get a better idea as the results are still somewhat confusing. For the moment I would take the results obtained with the second receiver in the ANAN with a grain of salt.
K9RX
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Re: 2018 QST Review ANAN-8000DLE

Postby K9RX » Thu Jun 27, 2019 1:57 pm

very interesting!

The values on the ANAN become worse when going from TX to RX (peak hold mode). If you stay on TX the values are better by approx. 10 dB on the ANAN. I assume this has to do with the automatic attenuator changing the setting when going from TX to RX.


what do you mean by this? I don't know what "peak hold mode" is. And also 'when going from TX to RX' ... i.e. using it normally?

I did have a guy, 2 different guys on 2 different nights, tell me my signal was very bad and looked like i was using a solid state amp (their words, again 2 different guys, 2 different nights ... both regional calls) ... yet the 8000 was showing it to be clean ... that concerned me a great deal...

Gary
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Re: 2018 QST Review ANAN-8000DLE

Postby DL5RBW » Fri Jul 05, 2019 5:39 pm

Gary,

the "Peak Hold" button is just right of the AVG button or below the screen configuration ((waterfall, panadapter etc.)

Make sure you start talking and let settle everything BEFORE clicking the "Peak" button otherwise you may see glitches from the switching process RX to TX or creaking of the microphone PTT switch and most important PureSignal needs some time to calculate and apply the proper parameters. Then stop talking but stay on TX, calculate the IMD from the dB values. Then release the PTT and go to RX. You should see the signal being freezed on the screen. Do the calculation again.
The same can be done with the 2-tone signal. Again, let settle things and THEN activate "Peak".

Seeing 3rd order TX IMD 45 to 50 dB down (with the amplifier in the predistiortion loop) on the spectrum analyzer and 60 dB down on the ANAN I assume this is about the limit. 50 dB however is quite good. Everything better than that can only be seen with signals being 30 to 40 dB over S9 and a noise level below S6 at the same time.

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