Wednesday 8 December 2021

SHERWOOD ENGINEERING TABLE

DOES IT MATTER?

When I started as a licensed operator, I was eager to find some sort of 'benchmark' so that I didn't make a newbie error and buy a duff radio. It didn't take me long to find the Sherwood Engineering Table.



At the time, this seemed like the be-all and end-all, so I gave it much credence and considered it to be more important than the opinions of YouTube reviewers (many of which were financially invested in their suppliers).

Over time I got a little wiser and it was when I purchased a Yaesu FT-DX101D that I realised there was so much more to buying a radio than an RMDR figure from a lab-test!

It made me ask myself a question relating to some older radios I'd either owned or used. The question was simple - did you consider that radio to be a really good receiver??

  • YAESU FT-1000MP Mk5 - Yes!!!
  • YAESU FT-DX3000 - Yes!!!
  • KENWOOD TS-2000 - Yes!!!
  • YAESU FT-891 - Yes!!!
  • Hell, I even consider the tiny BELKA DX to be an absolutely great receiver!
I'm sure that having the 'top-spot' in the Sherwood Table makes for great sales, but it certainly doesn't relate to a great operating experience! I very much disliked the FT-DX101D and ended up going back to an IC-7610.

As far as I was concerned, the two receivers (or should I say four, lol) had nothing between them - they were both superb - it all came down to preferred features and operating methods - and for me, I thought the Icom was the much better radio.

I don't doubt that if you sat down a few operators in front of an FT-1000MP Mk5, they'd be swooning over its superhet sweetness and yet it sits in 107th place in the Sherwood League. 
 

My little KX3 sits 10 places higher than my IC-7610 😮 Is it the better radio? I don't think so, 😂. These are just lab-numbers. Sure, they matter in terms of manufacturers trying to make constant improvements and after all, you can't improve if you don't measure.

But I have now come to realise that the Sherwood Table is not something I should refer to when considering the purchase of a new radio. 

UPDATE
Even though the FT-DX101 is at the top of the Sherwood Table, here's what people have said....

"I've tested extensively, hours and hours, the 101d against the 7610 in the last CQWWCW, in very crowded bands and with all the filters and all sort of conditions, above all comparing side by side very weak signals very near to very strong signals. NO differences at all. 

The 101 could not receive a signal better than 7610. In fact, the 7610 could receive the signals easier, faster, without so many adjustments. Icom 7610 offers much more (best waterfall, better software, more realiability, easier to get good results, better audio, with more bass and smooth, clean, soft sound, LAN, i/q output, play/record, menu system easier, parameters more adjustable , better noise blanker, etc, etc).

ROB SHERWOOD (Sherwood Engineering) 
The FTdx-101D measured better than the IC-7610 on one measurement only, dynamic range because it has a roofing filter.  My three 7610's have never been close to overloading from a local signal let alone a skip signal.

I spent the last two contest weekends (ARRL 160 and 10 meters) doing A/B comparisons between the 7610 and a K4D.  Both are direct sampling and by definition no roofing filters.  The 7610 won hands down on CW and SSB.  Thank goodness modern radios are firmware upgradable for feature improvements and bug fixes. The latest update to the 7610 (and other Icom transceivers) was the new scroll feature. This was a massive improvement for a contester the way the waterfall no longer smears / skews off at an angle when tuning.  

So Rob Sherwood himself has THREE IC-7610's!! I guess that speaks volumes about the value of the table in the "real world".
 
 
 
I recently saw a very sensible post on Groups.IO about this very subject....




Believing the Sherwood Engineering RX Performance List is a list of radios in there rank of performance is false. It is definitely NOT!

 

It is a list in the order of the radios’ 3rd order dynamic range measurements. (“DR3”)

BEFORE SDR, it was generally OK to consider this also a list in the order of ultimate performance.

Not so today, not by any means!

 

According to Rob, THE #1 Criteria for choosing a radio is . . . you have to enjoy using the radio.

And THIS is where the RGO-ONE excels!

 

The early SDR radios (i.e., Flex, with the 5000 being the flagship) topped the list in DR3 performance but their DR3 would fall by 20 dB when used in the presence of other near-by transmitters.   They were very poor radios for use at a multi-TX Field Day site, or a Multi/Multi contesting site.

But for “Home Alone” (i.e., Kevin), they were great radios… if you were OK with a radio having no knobs.

 

Later radios improved significantly, especially the high end radios.

The problem was overloading of the front-end digital circuitry (i.e., the Analog-to-Digital-Converter or ADC). 

 

Overcoming this is a two-sided sword.

  • On one hand, the advantage of these new radios is, you could monitor a broad frequency spectrum all at once.
  • On the other hand, to do that, you could not have ham-band specific bandpass filters (BPF’s).

 

The radios were soon improved in three ways:

1.       Careful gain management, with as little as possible front-end gain before the ADC’s.

2.       By adding switchable BPF’s, one for each ham band . . . or better yet, an analog front end using a Crystal roofing filter, then mixing it to baseband and on to the ADC’s.  But this ‘Hybrid’ front end is very expensive.
 

3.       By using a feature called (among other things) “IP+”, in which a signal is generated within the radio and dithered to the wanted signal. Its effectiveness is dependent on its clock speed and more important, the algorithms used to apply the dither.  There are significant differences in how effective this work from one radio type to the next. 

 

#1 As you can see from the above, “cheap” can’t get us a good receiver.

#2 does not help improve DR3 measurements because the two signals used are spaced just 2 kHz apart, and are the only signals the radios hear.  This is not indicative of our bands, especially during a contest.


#3 separates the men from the boys.  However, like #2, cannot really be measured in the lab.   We need a very crowded ham band to check this.

 

As a result, Rob will test all of the high-end radios in at least one major contest, such as CQWW DX, etc.

His evaluation of the radio after using it in a contest is not reflected in lab numbers, nor in his RX Performance List. For this you must read his Full Test Review of each radio.  In it he reports ALL of the lab measurements and then writes a page or 2 or more of comments on how he subjectively evaluated the radio during the contest.


These comments include statements about the ergonomics of the radios.  This includes using the manual controls and the software menus.  Again, there are huge differences in the radios.  They also include comments on audio clarity/distortion.  Rob has said he would not want to use a few of the radios which place high on his list, although he probably won’t say publicly which ones they are.  (‘Your’ mileage may differ.)


Finally:  Dirty Transmitters.  In the past there were huge differences in the different transmitters, and I don’t mean just IMD.  Composite noise is just as important, but it was never measured nor reported.  Since Rob (and others) have begun measuring and reporting this, one company who previously had very dirty transmitters, now has some of the cleanest transmitters available.


Rob’s Info ONLINE:

·       Full Reviews of the Radios:

o   https://www.dj0ip.de/sherwood-forest/sherwood-hf-xcvr-tests/

·       List of transmitters ranked by TX Composite Noise (bottom of page):

o   https://www.dj0ip.de/transceivers/tx-noise/

 

In summary,  of all of this, the things we like best about the RGO-ONE will be found in the comments of the full-review, not necessarily in the RX Performance List.   This will help spread the word, but only to those who take the time to read the full reviews.

IMO, the RGO-ONE is an outstanding radio for enthusiasts, but will probably never be first choice among those who win contests. … and that’s OK, because most hams have never and will never win a contest!

 

For now, the RGO-ONE remains an insider-tip.

 

73 - Rick, DJ0IP

(Nr. Frankfurt, Germany)

May the Sunspots be with Us!



Your comments would be welcome.

2e0fmi

3 comments:

VE9KK said...

Good morning Tom, like you, I too was hooked on the Sherwood tables at one time. Then over time I came to realize as you said it's not all about the numbers. The numbers do help, but they are not the be all and end all. I too very much like my 7610 but having said that the Elecraft K3 I had beat hands down the 7610 when it came to contesting and really close signals. That being said, 7610 is very good at close signals....it's not a K3 BUT in my humble opinion the 7610 for me is a much, much better radio.
It's a trade-off with specs and what it is you are looking for and need in a radio.
Very nice post,
73,
Mike
VE9KK

PE4BAS, Bas said...

Since I have no money for a IC-7610 I prefer the IC-7300. The difference between the IC-7300 and my old IC-706 is huge. Especially the receiver is much better in rejecting strong nearby signals during contesting. I once had the opportunity to test both the KX3 and the 7300 during the same contest. Personally I found the IC-7300 much more pleasant to listen to. 73, Bas

MadDogMcQ said...

Hi Bas, hope you're well. Yes, the 7300 is a brilliant receiver! Probably Icom's biggest success ever. When you were listening to the KX3, were you using the internal speaker? It is truly DIRE lol.

73, Tom. M7MCQ