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Author Topic: IC-7410 and IP3 Specification  (Read 4881 times)
N5VTU
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Posts: 358




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« on: June 16, 2011, 12:33:08 PM »

Hi all,

I was looking at the specifications on the IC-7410 as stated in a full page Icom advertisement in my Summer 2011 HRO catalog and notice that one of the features listed is a "+30dBm 3rd order intercept point (144MHz)".

I was under the impression that the IP3 rating is an indicator of the level of undesirable IMD signals due to mixing that appear within the rig's coverage bands only, not at frequencies way beyond the rig's capabilities.  So how does a +30dBm rating at 144Mhz have bearing on a HF/6m rig only?

Is my thinking correct?  Perhaps I'm confusing IP3 with another term.


Stephen
N5VTU
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ZENKI
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Posts: 916




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« Reply #1 on: June 18, 2011, 02:50:32 AM »

At what signal spacing? Icom has been running the IP3 marketing scam now for years on the IC7800 and IC7700, both of which have marginal performance against the well known top performing radios. It also does not help that the ARRL uses test procedures that make these Icom rigs look better than they really are. Icom does not have any radio that is as good as the Orion, K3 or FT5000. Whats worst is that in Europe non of Icoms modern offerings are not used in contesting because the receivers are lousy and the transmitters have too much phase noise, spurious products  and wide band IMD issues.

You can read about the issue here

http://www.df9ic.de/

So Icom can make  any claim  that it wants too and get away with. The bottom line when Sherwood and the other independent receiver performance people measure the 7410, the radio will be at the bottom of the receiver list just like Icoms other products. Unfortunately for Icom its receiver Architecture dictates the performance numbers. Icom should really be  moving to a true direct sampling/DUC architecture for its future products. Up conversion  and the cheap parts that they use in their radios cant deliver the performance hams expect. Then we have to start talking about transmitter IMD performance, I had both a IC7700 and IC7800 both of which had  transmitter IMD performance which was no better than a IC718. You would think if you payed 10,000 dollars for a radio that the transmitter IMD performance would be 1 or 2 grades better than the IC718! I am not impressed with Icom anymore they just all marketing hype and they just seem to recycle the same lame products over and over into new products without delivering real performance improvements. Just dont tell that guy in Canada this. If you say this on his Icom reflectors, he censors you by putting you on moderation and delaying your posts. A nice tactic while claiming that there is no censorship, right!

Icom should produce a radio like the ADAT transceiver using leading edge technology. I would not hold my breath though, the Japanese cant be innovators like Elecraft and ADAT. They have always been good at copying technology. The TS-590S is an example of this, nice performance but only halfway there!

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AE4RV
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« Reply #2 on: June 18, 2011, 07:28:50 AM »

Tell us how you really feel.
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N0YXB
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Posts: 304




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« Reply #3 on: June 18, 2011, 02:17:24 PM »

Zenki, stereotyping is so unnecessary.  If you're basing an entire country's innovativeness on a couple of brands of HF radios you're missing a lot.  The Japanese are indeed be innovators.  You might want to take a trip or two to Japan sometime.  Take a look at their automobiles, their wireless networks, their construction techniques to deal with earthquakes, etc, etc.  I believe in the days of reconstruction after WWII they probably did copy from others, but that was a long time ago and look how far they've come.  The Japanese do a lot of leading edge research in several different scientific fields.

Vince
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Vince
ZENKI
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« Reply #4 on: June 18, 2011, 07:52:32 PM »

I speak Japanese and have worked have worked there in the electronics industry, so my opinions are based on real life experience not some nasty stereotype.

You seem to forget who taught the Japanese all these techniques in manufacturing and quality control to the Japanese,,,,, William Edwards Deming. 

Very few Japanese innovations are uniquely Japanese, most ideas are seeded in the West. I have seen this so called Japanese copying(innovation) of Western ideas first hand being manipulated and molded into some kind of uniquely Japanese innovation. I am not racist and I love their culture and food.

Name 10 unique Japanese products of the last 20 years that are 100% unique Japanese ideas or products! All the products that the Japanese get credit for were American or European ideas   that just never took off and they later were developed into products

China is in exactly the same position as Japan was in the 50's, they just have the advantage of cheap slave labor. Eventually that will run out and they will need to innovate. Just copying and producing cheap goods only takes you so far in life. In Chinas case a  peoples revolution will occur before they wake up and start thinking  about innovation. Anything that is a Chinese innovation is copy of someone else''s products.

Besides where is Japan today? the economy has been in recession for the last 10 years because it cant re-invent  its economy and it cant compete with China. So much for Japanese innovation! The only thing that I will concede about Japan is that they know how to  produce quality products if they are manufactured in Japan. If you go to Japan today you would be shocked to see the same chinese junk that we buy in all the Japanese stores, made in Japan is long lost in history!

Zenki, stereotyping is so unnecessary.  If you're basing an entire country's innovativeness on a couple of brands of HF radios you're missing a lot.  The Japanese are indeed be innovators.  You might want to take a trip or two to Japan sometime.  Take a look at their automobiles, their wireless networks, their construction techniques to deal with earthquakes, etc, etc.  I believe in the days of reconstruction after WWII they probably did copy from others, but that was a long time ago and look how far they've come.  The Japanese do a lot of leading edge research in several different scientific fields.



Vince
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ZENKI
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« Reply #5 on: June 18, 2011, 08:07:39 PM »

Well does Icom have the best blocking  and IMD dynamic range numbers at signal spacings of 2khz or less? Is its transmitters the best performing? No is the answer too both questions.

If I want to go out now and buy the best and fastest car in the world I can go do so now. The speed and performance  of the best cars in the world is easily proven. Radios  that rely on marketing hype and the allure of a high price without delivering   wont win a performance race! The British car makers tried the same trick by bringing out expensive cars that were supposed to be prestigious cars, as we now know all these products were expensive lemons. At least if you claim that your radio has the best performance it should win the race  and its performance should be supported by facts or figures? The last time I checked non of these Icom radios were on the top of the receiver and transmitter numbers lists. I will agree that not everyone buys a radio on the basis of performance numbers, but at least these numbers can cut through the marketing hype. I like buying the best, I dont like buying products that pretend to be the best. I just cant afford a Rohde and Schwarz transceiver, so the K3 or the FT5000 will have to do!

Tell us how you really feel.
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G3RZP
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« Reply #6 on: June 19, 2011, 04:34:24 AM »

There are other questions. What instantaneous dynamic range do you need? The DR is determined by two factors - IP3 and phase noise. Extensive measurements show that in Europe on 7MHz, the AVERAGE amateur only needs 95 to 100 dB. These measurements were made in 2002 and repeated in 2007. They can be found in QEX for May/June 2002 and NCJ for March/April 2008. Incidentally, for the EU visitor to the US, the quietness of 7 MHz is amazing in comparison with home.

IP3 on its own is little use unless the phase noise is good. Drop the input by 6dB and the IP goes down, usually something between 12 and 18dB. At the same time, phase noise effects only go down 6dB. So if you have a number of lower level signals that don't give IMD problems, you do get the phase noise effects adding linearly.

There is also blocking, although quite is meant by that is not always clear - usually, it seems to be gain compression. Usually, by the time blocking is a problem, you have been introuble for some time with phase noise.....
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AE4RV
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« Reply #7 on: June 19, 2011, 04:43:23 AM »

Hi all,

I was looking at the specifications on the IC-7410 as stated in a full page Icom advertisement in my Summer 2011 HRO catalog and notice that one of the features listed is a "+30dBm 3rd order intercept point (144MHz)".

I was under the impression that the IP3 rating is an indicator of the level of undesirable IMD signals due to mixing that appear within the rig's coverage bands only, not at frequencies way beyond the rig's capabilities.  So how does a +30dBm rating at 144Mhz have bearing on a HF/6m rig only?

Is my thinking correct?  Perhaps I'm confusing IP3 with another term.


Stephen
N5VTU


I have that catalog with the ad also. That looks like a misprint. It says 14MHZ here:
http://www.radioworld.co.uk/catalog/icom-ic7410-p-7508.html

That's an unfortunate typo since it implies 2 meter operation which it doesn't have. This may confuse those who expect 2 meters in a radio that is replacing the 746pro.
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WE1X
Member

Posts: 320




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« Reply #8 on: June 19, 2011, 05:24:51 AM »

ZENKI...a couple of things worth noting:

Regarding Japanese innovation (or lack thereof): you're sort of correct, but not spot on. Yes, the Japanese leverage innovations and inventions (core technology, prototype products, even finished products) coming from the West. However, the Japanese have been particularly adept at commercializing those innovations and technologies often through re-design, re-packaging or new applications. Considerable innovation and risk have come from and been assumed by the Japanese to make this happen. Further, it frequently happened by the reluctance (if not outright refusal) of Western (particularly U.S.) manufacturers and venture capitalists to do so. An absolute classic example is LCD screen technology: pioneered (design through initial prototype) by two U.S. technology entrepreneurs back in the late 1970s or early 1980s  who could not raise interest among manufacturers and investors to take the next steps to commercialization....with the exception of the Japanese who ran with it.  Another example (however trite it may seem) is the Sony Walkman...the repackaging of existing transistor radio and recorder playback technologies to create a whole new product line for personal entertainment.  As for Deming: He turned to the Japanese and they accepted him when U.S. manufacturers elected not to do so.  Again, another example of the Japanese's insight into new techniques of doing things and applying it in an exceptional manner (while U.S. manufacturers failed to do so until the Japanese automotive industry almost put their U.S. competitors out of business).

Regarding receiver specifications: Again you're sort of correct, but not spot on. Yes, independent receiver tests such as Rob Sherwood's clearly indicate Icom rigs fail to make the top of the list. Yes, even the Icom 7800 with its high price tag is a "marginal" performer when compared to the K3 and other rigs at the top and at a fraction of the price. However, top rankings in receiver performance do not necessarily indicate those rigs are the best. Why do I say this? Two fundamental reasons. First, as Rob Sherwood has stated on other posts there is far more to selecting a rig than receiver specs. Reasons could be fit and finish, operating ergonomics, audio quality. Note that Rob often uses his trusty Icom 781 as a reference radio and for some contests.  Second, the vast majority of hams lack the antenna systems to warrant rigs in with the best specs. Regardless of whether the radio is an Orion, K3, FT-5000, etc. the operator is not going to dramatically benefit from the best specs if he/she is using a dipole at 30 feet. In other words, it's a case of spec overkill. Unfortunately, test results such as Sherwood's have been misused by the manufacturers of "elite" rigs to market their products and by owners to generate "spec envy". Note I've used various Icom rigs for many years, several Yaesu rigs, a K3 and Kenwood TS-590....in other words a mix of elite and not-so-elite.  While I liked the K3 I found the audio fatiguing, the ergonomics marginal and two failures (one requiring the rig sent back to Elecraft for 6 weeks) issues that required me to sell the rig .... even though it was/is at the top of the receiver spec list.

Harry WE1X
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N5VTU
Member

Posts: 358




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« Reply #9 on: June 19, 2011, 08:43:26 AM »

Thanks for the replies.  My initial question had nothing to do with Icom radios in general or opinions of what is right/wrong with them or to start a thread with an anti-Icom theme.  It was only trying to understand how an IP3 specification (any value) that was stated relative to 144MHz had any merit for a HF/6m only rig.  In looking at the link the AE4RV provided, it does appear that the IP3 spec is a typo, and should have been 14MHz, not 144MHz.

Thanks,
Stephen
N5VTU
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AE4RV
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« Reply #10 on: June 19, 2011, 09:17:10 AM »

Stephen, for what it's worth I really like my 7410. It is a noticeable upgrade to my 746pro in almost every way that I look at it.

73, Geoff AE4RV
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N0SYA
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Posts: 356




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« Reply #11 on: June 19, 2011, 09:40:07 AM »

Thanks for the replies.  My initial question had nothing to do with Icom radios in general or opinions of what is right/wrong with them or to start a thread with an anti-Icom theme.  It was only trying to understand how an IP3 specification (any value) that was stated relative to 144MHz had any merit for a HF/6m only rig.  In looking at the link the AE4RV provided, it does appear that the IP3 spec is a typo, and should have been 14MHz, not 144MHz.

Hi
To answer your question, there might be no relevance between ip3 figures of the same rig at 144MHz and ip3 at 14MHz due to use of different front ends (preamp or lack of one, bandpass filtering, mixer) for hf and vhf, if such is the case. I find that most rigs have worse ip3 above hf/6m than below it for one reason or another.
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If you have a clumsy child, you make them wear a helmet. If you have death prone children, you keep a few clones of them in your lab.
ZENKI
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Posts: 916




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« Reply #12 on: June 22, 2011, 03:54:36 AM »

Cant disagree with your analysis on the Japanese and innovation. Your explanation is eloquent.

On the radios I partially agree. I agree with your analysis of the K3. Its AGC and noisy receiver syndrome drives me nuts. The K3 is terrible receiver to use on the low bands with even mild QRN around. I was shocked when I turned on a good analog  receiver and compared the two. Many users have stated  this about the K3's receiver, however these comments have been dismissed as incompetent  users who dont know what they doing. I know what I am hearing. Then we have the birdies and all the other problems that you mentioned about the K3;s design. The issue about the high inband  RX audio IMD is another issue. Anyway I have two K3's and other radios. I loaned my K3 to a old ham who had a old TS530S. He called me up on the phone and said come take this terrible receiver back! I said are your joking. He said no come here and have a listen. While the TS530S had bad IF HISS the radio sounded so much better and full bodied on RX. The CW note   sounded pure and full and the K3 sounded poor by comparison. If you did a blindfold test listening to these two radios, you would swear that the K3's received signal strength was  almost half of the TS530S even though they were reading roughly the same on the S-meter. I wont go on because this will just infuriate  the many K3 users who love this radio
But its not my favorite by a long  shot despite its impressive RX specifications.

Your comments about the radios intended environment and how you use it are correct. There is little point owning a high performance radio if you live in the city with S7 noise and you have a low G5RV. You certainly will never be in a position to exploit the best receivers  in the world. The other problems is that most hams dirty transmitters will also define how much real dynamic range you can use. Icom  still needs a few more Db of  dynamic range on most of its radios. I refuse to pay so much for a radio with such low IMD dynamic range numbers and equally poor TX IMD numbers. ALC overshoot should not even exist on a IC7800 at 10K$

In short my definition of a good transceiver is one that has both an excellent transmitter and receiver. The  TX IMD must be low and the RX must be free of inband IMD distortion. Unfortunately as Rob  has mentioned on numerous occasions  most manufacturers ignore all the important areas that makes a radio  truly the best in the world. These would be good dynamic range numbers, low inband audio IMD(how good the RX sounds),  a decent audio amplifier, good TX IMD(at least -40db below pep) and most importantly good non fatiguing ergonomics.

Seriously what Japanese  manufacturers is going to deliver a radio that will meet  all these key requirements? We have been on the same non performance platform for the last 10 years! Elecraft set the standard with the K3's receiver, however its lacking in so many other areas. Icom has some very nice looking radios without  the best TX or RX performance. The Yaesu FT5000 seems to have both a good transmitter and receiver however I cant  comment on the other aspects of its design.

I am close to being in the grave, I doubt that I will see the ultimate transceiver in the next 2 sunspot cycles! I am impressed by the ADAT radio, however I have not seen independent test data of this radio. However it gives us glimpse of what can be achieved by using the most advanced techniques that exist, if only Icom could something like the ADAT with Icoms impressive layout, ergonomics and sheer  good looks!

ZENKI...a couple of things worth noting:

Regarding Japanese innovation (or lack thereof): you're sort of correct, but not spot on. Yes, the Japanese leverage innovations and inventions (core technology, prototype products, even finished products) coming from the West. However, the Japanese have been particularly adept at commercializing those innovations and technologies often through re-design, re-packaging or new applications. Considerable innovation and risk have come from and been assumed by the Japanese to make this happen. Further, it frequently happened by the reluctance (if not outright refusal) of Western (particularly U.S.) manufacturers and venture capitalists to do so. An absolute classic example is LCD screen technology: pioneered (design through initial prototype) by two U.S. technology entrepreneurs back in the late 1970s or early 1980s  who could not raise interest among manufacturers and investors to take the next steps to commercialization....with the exception of the Japanese who ran with it.  Another example (however trite it may seem) is the Sony Walkman...the repackaging of existing transistor radio and recorder playback technologies to create a whole new product line for personal entertainment.  As for Deming: He turned to the Japanese and they accepted him when U.S. manufacturers elected not to do so.  Again, another example of the Japanese's insight into new techniques of doing things and applying it in an exceptional manner (while U.S. manufacturers failed to do so until the Japanese automotive industry almost put their U.S. competitors out of business).

Regarding receiver specifications: Again you're sort of correct, but not spot on. Yes, independent receiver tests such as Rob Sherwood's clearly indicate Icom rigs fail to make the top of the list. Yes, even the Icom 7800 with its high price tag is a "marginal" performer when compared to the K3 and other rigs at the top and at a fraction of the price. However, top rankings in receiver performance do not necessarily indicate those rigs are the best. Why do I say this? Two fundamental reasons. First, as Rob Sherwood has stated on other posts there is far more to selecting a rig than receiver specs. Reasons could be fit and finish, operating ergonomics, audio quality. Note that Rob often uses his trusty Icom 781 as a reference radio and for some contests.  Second, the vast majority of hams lack the antenna systems to warrant rigs in with the best specs. Regardless of whether the radio is an Orion, K3, FT-5000, etc. the operator is not going to dramatically benefit from the best specs if he/she is using a dipole at 30 feet. In other words, it's a case of spec overkill. Unfortunately, test results such as Sherwood's have been misused by the manufacturers of "elite" rigs to market their products and by owners to generate "spec envy". Note I've used various Icom rigs for many years, several Yaesu rigs, a K3 and Kenwood TS-590....in other words a mix of elite and not-so-elite.  While I liked the K3 I found the audio fatiguing, the ergonomics marginal and two failures (one requiring the rig sent back to Elecraft for 6 weeks) issues that required me to sell the rig .... even though it was/is at the top of the receiver spec list.

Harry WE1X
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ZENKI
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« Reply #13 on: June 22, 2011, 03:58:40 AM »

Its not a anti Icom theme. You mentioned the brand and its well known fact that Icoms 3rd order IP figures are grossly misleading as it applies to the real world. be it VHF or HF the higher the IP figures at especially close signal spacings the better the receiver. While there other factors like TX phase noise and IMD that will come into play well before the receiver front end collapse, IP3 figures are important It could be argued that IP3 is only a lab figure of merit that may never occur in the real world, it is indicative of performance. 

Thanks for the replies.  My initial question had nothing to do with Icom radios in general or opinions of what is right/wrong with them or to start a thread with an anti-Icom theme.  It was only trying to understand how an IP3 specification (any value) that was stated relative to 144MHz had any merit for a HF/6m only rig.  In looking at the link the AE4RV provided, it does appear that the IP3 spec is a typo, and should have been 14MHz, not 144MHz.

Thanks,
Stephen
N5VTU
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ZENKI
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Posts: 916




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« Reply #14 on: June 22, 2011, 04:17:08 AM »

The DF9IC link explains exactly   what the exact requirements are for VHF/UHF contest receiver and transmitter performance.

It clearly shows that a good HF receiver when used with a good transverter outperforms just about all VHF/UHF commercial transceivers.

So regardless of what manufacturer produces  a VHF or UHF all mode transceivers their performance is lacking all aspects when it comes too transmitter and receiver performance.

Just as the debate on receiver performance has change market dynamics in the the HF radio market, this change towards  better receiver performance in UHF and VHF radios has yet to come to this market. Most of the all mode all band radios are terrible compromise that does not meet the needs of serious operators. However as most  hams lived with substandard HF radios as we learned how good or bad they perform, VHF and UHF operators are living with the same compromises until something better comes along. In Europe the Kenwood TS2000 and the Icom 910H are not good enough and neither will   the new Icom 9100 be the best. People will still buy them regardless of performance, thats just the way hams are. Brand name and  using the latest is more important than having the best performance numbers.

We unlikely to ever see a contest grade VHF/UHF all mode transceiver from any of the Japanese manufacturers.  The Japanese have never displayed interest in performance orientated radios until their sales start to hurt. This is unlikely to happen in the VHF or UHF market because simply their is no competition.
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