IC7300 first test datas

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  • Updated 3 years ago
from a email of Rick DJ0IP:


This is HOT off the press.

Rob has been busy measuring the IC-7300 and IC-7851.

He has both radios on the bench right now.

... further read here:


http://www.dj0ip.de/sherwood-forest/sherwood-xcvr-tests/icom-ic-7300/


.... On the 7300, the data looks kind of OK, about like the 7410 or 7600, but there is a catch.

With the older radios, turning on the IP+ improves the BDR3 significantly.

With the 7300 it “looks like” it does but there is still a problem with overload.

 

Specifically, Rob writes:

 

Blocking measurement was limited by the ADC overload indicator “OVF”

Overload with a single signal occurs at -10 dBm

While dynamic range is increased significantly with IP+ enabled, the overload

point remains -10 dBm.



73 Chris DL5NAM

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Chris DL5NAM

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Posted 3 years ago

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SteveJ

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There is one thing that the 7300 does have a better rating than the Flex is the RX latency.  The TX latency is being tested now and should be reported soon. The user reports for the 7300 have been excellent. This is going to be a good seller for Icom given the price point.

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Barry N1EU

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IC-7300 shape factor measured 1.29:1 by Rob Sherwood.
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Lewis Cheek

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Speaking of RX latency, I SURE hope FRS does something soon to improve cw performance. Once Maestro is released how about a focus on improving performance? :)

Lew
N4CO
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Doug Hall

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"IC-7300 shape factor measured 1.29:1 by Rob Sherwood."

Well that's probably a reason for the low RX latency on the 7300. I've measured the shape factor of the 2.4 kHz filter in my 6300 at less than 1.05 using two different methods. (I got 1.04 using one method and 1.03 using another.) My results aren't lab-worthy, but I think they're reasonably close. I don't know the sample rate of the radios in question but I could believe that for a given sample rate you'd need maybe 8X the taps to get this kind of improvement in shape factor, all other things being equal. More taps, more latency. As Time said, you don't get something for nothing.

"Those two latencies make me think that the Icom uses IIR filtering, while the Flex uses FIR filtering."

I'd be surprised to see any DDC receiver using IIR filters. I seem to remember reading somewhere that if you are implementing a decimating filter there is a great advantage in using FIR since all the terms don't have to be computed. With the feedback of an IIR filter I think that's not the case. And I'd think you would want the linear phase response of the FIR filter for any data modes.

Disclaimer - I'm not an SDR guru by any means. I could certainly be wrong about this.

73,
Doug K4DSP
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Doug Hall

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I don't know why this showed up twice. I can't delete the duplicate, nor can I edit either one.
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Doug Hall

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I did a little more research on Rob's 7300 measurements. The filter shape factor quoted above was for the 500 Hz CW filter, so I wasn't comparing apples to apples. The 7300 2.4 kHz filter is even worse, with a shape factor of approx. 1.5:1. Not much better (or any better) than some crystal filters.

Personally the RX latency in my 6300 has nearly zero impact on my operating. The filter shape factor has a HUGE impact, however.
73,
Doug K4DSP
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DrTeeth

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I have just read on another forum that 60m is not available in the European models. The poster speculated that it could be because there is support for the 4m band instead.
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Alex - DH2ID, Elmer

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Guy, I found this by Marcus, PA2DB

>Remove bottom and find the diode matrix (near big chip)
>Open RX 0.030-74.8Mhz (REMOVE D416)
>Open TX 0.1-74.8Mhz (REMOVE D422) (D419 is and must be in)
>** Only Open TX 60Mtr 5.255-5.405Mhz (REMOVE D405)

http://yo3hjv.blogspot.de/2016/03/icom-ic-7300-marscap-extended-tx.html
http://wsplc.com/icom-ic-7300-hf-4m.html is doing it for free :-p
(Edited)
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DrTeeth

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Hi Alex,

What are those Dxxx's? Jumpers or components?

Thanks,

Guy
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Tim - W4TME, Customer Experience Manager

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SMT diodes
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KY6LA - Howard, Elmer

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People have been Modifying Icom, Kenwood and Yaesu rigs for years.  www.mods.dk

I have used the snip the control matrix diode trick on my old Icoms to extend their range ...  no need to solder. just use a needle nose pliers and break the appropriate diode..

Yes it will theoretically void the warranty.. if they catch you.. but in my experience no technician ever looks that closely when you bring it in for service....

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Walt - KZ1F

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Well sure, I did the mod on the ts-530 to open the WARC bands but it wasn't u der warranty then. I also did major reconstruction when the final went or something else went taking out the final and melting a chunk of the circuit board. As one would suspect, it was out of warranty then. To open up 60m, ID send it back to an authorized service center. After all, we're talking about people with, sorry, failing eyesight and unsteady hands messing with smt.
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Chris DL5NAM

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... further rumor : in manual of TRX ( i never read it, i dont have it) .... use TRX with smaller antennas (~ overload) -
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DrTeeth

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@ Chris - Thanks for that.

@ Alex - Dentists use little plastic sticks with a blob of sticky stuff at the end which could be useful. They are not cheap. Here is a link http://www.ec21.com/product-details/Dental-Restoration-Holder-Inlay-Carrier--8760276.html. I do not know the proper term for them as I used to ask my nurse for a "sticky stick thingy...", and that works over the phone but not when searching a catalogue!
(Edited)
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Alex - DH2ID, Elmer

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@Walt: yes, warranty will be void
@Guy: superglue does the job
@all:  Max bandwidth is an issue, seems not to go above 3.6kHz in SSB-D
          Don't know if one can use the IF output of 12kHz (for DRM)
          for digimodes like JT65/9
BTW I like my KX3, which is another exampe of "SDR" radios, which have
excellent receivers, way up on the Sherwood list, but have none of the
flexibility the FlexRadios have!
(Edited)
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DrTeeth

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@ Alex,

Just be careful you do not end up walking around with a transceiver stuck to your finger, hi hi. It would be a real PITA to schlep it around for a couple of weeks.
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Alex - DH2ID, Elmer

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.... .. .... .. but that will be extremely unlikely, because I do not intend to buy
the 7300. I'll keep my trusty old IC-756pro for PACTOR and CW .... .. .... ..
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DrTeeth

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I would love to get hold of a working and in good condition Yaesu FT200, the rig I got when first licensed.