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Author Topic: Sherwood Engineering Receiver Test Data  (Read 2266 times)

KF5LJW

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Sherwood Engineering Receiver Test Data
« on: March 06, 2021, 07:10:02 PM »

I am sure most of you know about the website. I have no dispute with the rankings. Some might debate the order of the top ten, but not much debate the top 10 deserve to be there. 

What is odd I do not see any straight up receivers, just transceivers.  Perhaps there are some on the list and I just not familiar the product. Back to the top-rated models and you will quickly notice most are SDR which is no surprise. The other point is they all cost several thousand dollars. You are paying top dollar for the Receiver. A transmitter is just a transmitter. 

So why no receivers like an SDR? Is it because they overlooked and dismissed? Or is there something else going on? Affording the benefit of a doubt, I could assume they dismissed them because many are junk Dongles targeted at low ball hams and enthusiast. However, there are some exceptions. Example AirSpy HF+ Discovery is outstanding. Its performance equals exceed most of the top ten. Not to mention can do things no ham receiver can do or ever will do. I have two units and have taken one to many ham friend’s homes with high dollar rigs in the top 10. All but one now uses a $170 RX.

No magic going on here. The use the same DAC as commercial LMR, cellular and high-end ham transceiver. They use open-source code with thousands of add-ons to do about anything you want. I use one of mine integrated into my home A/V system as a FM receiver, a FM HD receiver with CD quality sound, and a high-fidelity AM SW RX because I like to listen to WTNN at night and hear the old rock classics and ham related stuff. Kind of cool having a dinner party or friends over in the man cave with a waterfall and the other displays that come with it on a screen the size of a wall.

So for you budget minded hams, look into a SDR receiver, no reason to spend several thousand dollars. You can have the best for a lot less and run circles around a ham transceiver for less than $200. Any ole two-bit transmitter will do. Have mine setup with a touch-screen monitor. See a signal on the waterfall, touch it, and the SDR switches to that frequency and modulation mode, then sends the data to my hf rig si I can TX if I want. Will even decode most CW. Look ma no hands.   
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K6AER

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Re: Sherwood Engineering Receiver Test Data
« Reply #1 on: March 06, 2021, 07:22:43 PM »

When you are looking at 2 KHz dynamic range of over 100 dB (top ten transceivers) a $140 SDR dongle is not worth mentioning. Please name a SDR dongle that has a 2 KHz adjacent dynamic range of 110 dB?

You dismiss the spectral purity of top transceivers but believe me when you add a amplifier and a  4 element beam at 100 feet the transmitter performance is very telling.
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KF5LJW

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Re: Sherwood Engineering Receiver Test Data
« Reply #2 on: March 06, 2021, 09:15:34 PM »

When you are looking at 2 KHz dynamic range of over 100 dB (top ten transceivers) a $140 SDR dongle is not worth mentioning.
Me thinks you have an over site lumping single Dongles together. I get it. I am not talking about 8 and 12 bit codacs as those are only capable 72 dBnr. It uses 18-bit A/D with 108 dynamic range.

They are not built like a Dongle. They have solid metal case with 2 RF Inputs with HF selectors. With the digital filtering and processing makes it powerful and easy to use. You would be pleasantly supersized. Or perhaps not and have troubling facing something so small and compact works so go. You can see some of the possibility in QRP rigs.

All I am say here is try one. You might like what you find and what you can do with the. 
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G4AON

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Re: Sherwood Engineering Receiver Test Data
« Reply #3 on: March 07, 2021, 12:01:45 AM »

Me thinks you have an over site lumping single Dongles together. I get it. I am not talking about 8 and 12 bit codacs as those are only capable 72 dBnr. It uses 18-bit A/D with 108 dynamic range.
What model are you referring to that has this apparent performance for less than $200?

73 Dave
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W6RZ

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Re: Sherwood Engineering Receiver Test Data
« Reply #4 on: March 07, 2021, 02:24:11 AM »

You have to compare apples to apples. The Sherwood list is ranked by 3rd order intermodulation dynamic range at 2 kHz tone spacing.

This link tested the Airspy HF+ Discovery 3rd order intermodulation dynamic range to be 84 dB.

http://www.dc4ku.darc.de/AIRSPY_Test_English.pdf

That's a very good figure, but not top 10. It puts the Airspy at position 41.
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W1VT

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Re: Sherwood Engineering Receiver Test Data
« Reply #5 on: March 07, 2021, 05:55:12 AM »

Dynamic range isn't the only place where receivers fall short of theoretical expectations.

There are now easy to use low noise amplifiers in the 1/2 dB NF range but it is very hard to get a 1 dB NF system noise figure if you are selling a 100W transceiver.

Zak W1VT
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N2DTS

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Re: Sherwood Engineering Receiver Test Data
« Reply #6 on: March 07, 2021, 07:21:56 AM »

USB latency makes it useless for some things.
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K3FHP

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Re: Sherwood Engineering Receiver Test Data
« Reply #7 on: March 07, 2021, 07:44:23 AM »

The Sherwood list DOES show the IC-R8500 receiver as #4 on the list, so Rx are included.  The new FTdx-10 is now #3 and it is under 2K(the FTdx-101 is at #1) and has pushed my venerable KX-3 to #11.  In arduous use such as at a 4A field day operation, the inexpensive SDRs show their shortcomings in overload situations.  They are wonderful toys and useful tools....I have 3 various RSP units from SDR Play and the are small miracles(IMHO) but are not in the same category as the modern HF transceiver receivers in all situations but whey are not in the same category or use.  The right tool for the right job.  The government-commercial use of 30-5Ghz sdr modules costing 20-30K each and there is some reason for that, as they ares yet in another category. 

Rather than worry that they are not on the top of some list, I just use and enjoy mine.

K3FHP
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N6YWU

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Re: Sherwood Engineering Receiver Test Data
« Reply #8 on: March 07, 2021, 11:17:20 AM »

The Sherwood rankings seems to be biased towards transceiver use in multi-op contest settings. 

A SWL (and likely the vast majority or amateur operators) are rarely if ever listening to Dx while sited near multiple QRO transmitters on nearly the same frequency, so receivers for SWL rarely have the bigger more expensive filters required for such extreme purposes.

BTW, those 8 and 12 bit direct sampling SDRs can have far more than 72 dB of dynamic range in actual use, due to DSP processing gain.
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N2DTS

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Re: Sherwood Engineering Receiver Test Data
« Reply #9 on: March 11, 2021, 04:46:46 PM »

The Perseus is #18 on the list, still good after what, 15 years?
The first two pages on the list are all very good and it would be hard to tell the difference between most.

Some of the downconverting radios are quite good but have images and birdies like the early flex radios on some bands.
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K4FMH

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Re: Sherwood Engineering Receiver Test Data
« Reply #10 on: March 16, 2021, 12:06:48 PM »

I am sure most of you know about the website. I have no dispute with the rankings. Some might debate the order of the top ten, but not much debate the top 10 deserve to be there. 

What is odd I do not see any straight up receivers, just transceivers.  Perhaps there are some on the list and I just not familiar the product. Back to the top-rated models and you will quickly notice most are SDR which is no surprise. The other point is they all cost several thousand dollars. You are paying top dollar for the Receiver. A transmitter is just a transmitter. 

So why no receivers like an SDR? Is it because they overlooked and dismissed? Or is there something else going on? Affording the benefit of a doubt, I could assume they dismissed them because many are junk Dongles targeted at low ball hams and enthusiast. However, there are some exceptions. Example AirSpy HF+ Discovery is outstanding. Its performance equals exceed most of the top ten. Not to mention can do things no ham receiver can do or ever will do. I have two units and have taken one to many ham friend’s homes with high dollar rigs in the top 10. All but one now uses a $170 RX.

No magic going on here. The use the same DAC as commercial LMR, cellular and high-end ham transceiver. They use open-source code with thousands of add-ons to do about anything you want. I use one of mine integrated into my home A/V system as a FM receiver, a FM HD receiver with CD quality sound, and a high-fidelity AM SW RX because I like to listen to WTNN at night and hear the old rock classics and ham related stuff. Kind of cool having a dinner party or friends over in the man cave with a waterfall and the other displays that come with it on a screen the size of a wall.

So for you budget minded hams, look into a SDR receiver, no reason to spend several thousand dollars. You can have the best for a lot less and run circles around a ham transceiver for less than $200. Any ole two-bit transmitter will do. Have mine setup with a touch-screen monitor. See a signal on the waterfall, touch it, and the SDR switches to that frequency and modulation mode, then sends the data to my hf rig si I can TX if I want. Will even decode most CW. Look ma no hands.   

Hi,

Keep in mind: Rob Sherwood does this for no payment, won't accept rigs directly from manufacturers, and publishes the results from his workbench test gear. He states this but folks don't read the information before quibbling: it's ranked solely on the basis of the narrow dynamic range figure. You really can't quibble with Rob's test results unless you have knowledge that he made a mistake in his bench tests. Hardly! Why does he rank them on the close-in DR? Because he is an avid CW contester and he says that's the most important measurement for him! And he states that plainly on this website. He either buys rigs to test or borrows them from colleagues (I just sent him my Xiegu G90, and SDR based rig, still in the box. That should appear in the near future on his website. Rob does not have any cash cow with which to purchase any and all rigs for your reviewing pleasure.

Now, you (or I) may not be either a CW operator or CW contester. So he provides 9 different bench measurements that cover much of the characteristics of the receiver in a rig (whether a receiver or transceiver). You can sort his table as you wish (you can scrape the web table into a spreadsheet). But I recently published a paper which I combined all 9 of his measurements into a single index that I called the Sherwood Performance Index. The two part article is in the previous and current issues of the ARRL National Contesting Journal, free to all members. I've given several talks to clubs that are available on Youtube about the research. Here's one to a club in England: https://youtu.be/Bw_G6-EdrwU.

Rob's work stands on it's own. He differs on some test procedures with the ARRL. Adam Farson has some ideas and methods he's proposed to measure SDR receivers. You might Google his website and do some reading.

Best wishes,

Frank
K4FMH
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KF5LJW

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Re: Sherwood Engineering Receiver Test Data
« Reply #11 on: March 16, 2021, 05:14:36 PM »

You really can't quibble with Rob's test results unless you have knowledge that he made a mistake in his bench tests.
Thank you Frank. No quibbling on the test results. I use his numbers and understand what they mean, and have a different priority and know how to filter a spreadsheet to get what I want to see. I do appreciate that.

So who is going to send him an Airspy HF+ Discovery? 
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K4FMH

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Re: Sherwood Engineering Receiver Test Data
« Reply #12 on: March 17, 2021, 01:31:51 PM »

You really can't quibble with Rob's test results unless you have knowledge that he made a mistake in his bench tests.
Thank you Frank. No quibbling on the test results. I use his numbers and understand what they mean, and have a different priority and know how to filter a spreadsheet to get what I want to see. I do appreciate that.

So who is going to send him an Airspy HF+ Discovery?

Well, do you have one? But contact Rob first. He may not have an interest in testing it....

Frank
K4FMH
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KM1H

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Re: Sherwood Engineering Receiver Test Data
« Reply #13 on: March 18, 2021, 04:06:25 PM »

The Sherwood list DOES show the IC-R8500 receiver as #4 on the list, so Rx are included.  The new FTdx-10 is now #3 and it is under 2K(the FTdx-101 is at #1) and has pushed my venerable KX-3 to #11.  In arduous use such as at a 4A field day operation, the inexpensive SDRs show their shortcomings in overload situations.  They are wonderful toys and useful tools....I have 3 various RSP units from SDR Play and the are small miracles(IMHO) but are not in the same category as the modern HF transceiver receivers in all situations but whey are not in the same category or use.  The right tool for the right job.  The government-commercial use of 30-5Ghz sdr modules costing 20-30K each and there is some reason for that, as they ares yet in another category. 

Rather than worry that they are not on the top of some list, I just use and enjoy mine.

K3FHP

I really like my R8500 but never realized it was that good!  I use it often to track down  crud generated by commercial users on other hills in the area.
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W6RZ

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Re: Sherwood Engineering Receiver Test Data
« Reply #14 on: March 18, 2021, 04:36:39 PM »

I really like my R8500 but never realized it was that good!  I use it often to track down  crud generated by commercial users on other hills in the area.

He meant the IC-R8600. The R8500 is near the bottom of the list.
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