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Author Topic: IC-7610 Ragchewing & Review Requests Thread  (Read 3066 times)
VK3BL
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« on: November 17, 2017, 08:27:20 PM »

Hey everyone,

Here's a video I made of a quick ragchew using the IC-7610.  We had tremendous signals on 40M during the day today - a friend Brenton VK3CM was reaching 40dB over 9!

Hopefully the video gets a few laughs an demonstrates what the received audio is like through a typical external speaker.

https://youtu.be/uWqmDv0TMmA

Today I recorded the aforementioned video and a menu overview that covers the IC-7610 (and IC-7300, IC-7100 mostly) menu.  Its actually really long as there are lots of options etc.

The menu overview is here: https://youtu.be/0m1XzUtZt8E

Please let me know what else you would like to see, and even other radios you're interested in me reviewing / covering.  Weak signal stuff is a little hard at the moment as we're a few weeks off summer and there is no shortages of static crashes, but I'll try and get it done. Smiley

73,

Jarrad VK3BL
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J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
VE3WGO
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« Reply #1 on: November 18, 2017, 08:30:23 AM »

Many thanks for posting your great videos, Jarrad!  

How good does an external display (for example the one above the radio on your desk) look to your eyes up close, when connected to the 7610's rear panel DVI output connector?  Is it smooth or is it just bigger fuzzy low resolution?

Also, have you found a receiving conditions instance where the 7610 with the digital preselectors can show off their preselecting skills when compared to a more commodity receiver in say, your 7100 radio?  I imagine it's a lot better, but what do you think?

Finally, do you have any idea how clean (or not) the transmitter output is?  Icom appears to be generating the Tx signal directly digital to RF, into a D/A converter, ie a Digital Upconverter, so there is the potential for this Tx signal to be very clean if the PA is linear enough.

Just my musings...

73, Ed VE3WGO
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VK3BL
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« Reply #2 on: November 18, 2017, 02:14:49 PM »

Many thanks for posting your great videos, Jarrad!  

How good does an external display (for example the one above the radio on your desk) look to your eyes up close, when connected to the 7610's rear panel DVI output connector?  Is it smooth or is it just bigger fuzzy low resolution?

Also, have you found a receiving conditions instance where the 7610 with the digital preselectors can show off their preselecting skills when compared to a more commodity receiver in say, your 7100 radio?  I imagine it's a lot better, but what do you think?

Finally, do you have any idea how clean (or not) the transmitter output is?  Icom appears to be generating the Tx signal directly digital to RF, into a D/A converter, ie a Digital Upconverter, so there is the potential for this Tx signal to be very clean if the PA is linear enough.

Just my musings...

73, Ed VE3WGO

Dear Ed,

Thanks for the reply! Smiley

I'll shoot a video with an external display today - its been the most popular question by FAR.  I'm expecting it to look quite 'blocky' on a big screen, as the resolution can only be set to 800x480 (16:9) or 800x600 (4:3).   A few a hoping for a 'surprise' when the monitor is connected in the form of extra resolution options Smiley

Re: the transmitter, I only have anecdotal reports.  There are some nice features that should allow it to be fine tuned, such as the ability to alter the drive level to the finals. 

I do have an SDRPlay RSP2 and a nice dummy load, so I will try and get some testing done.  I don't have the requisite equipment to do a lab grade 2 tone, but I can easily do an FFT Averaged (aka time lapse) test using Phone input, which should yield a more realistic result; it should reflect on air performance.

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J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
ZENKI
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« Reply #3 on: November 21, 2017, 12:58:13 AM »

Can you measure the  2 tone transmit IMD? You have a SDRplay so you could do it. You can download 2 tone software and use that for the generator. Most sound card programs produce clean 2 tones that are sufficient for IMD measurement.

I have heard your  signal on the remote SDR receiver in VK3 which I use to check long path 40meters. I have also heard VK2JE  with a IC7610 on long path 20 meters  at about 0600/0700GMT. Just as an anecdotal observation, the IC7610 does have a  lot of IMD close  to signal that is  a very distinctive transmit pattern. This might also be that IMD generator called the SPE 1.3KFA!  Again 2 tone IMD measurements are purely an engineering test parameter that has little bearing on the real dynamic IMD figures using a real voice.

The processor seems to be a very low distortion unit that produces  good punch without excessive processing. Which should be the case with a DUC transmitter. Its a pity that they did not give users the ability to store  multiple transmit profiles. Listening to the unprocessed signal seems to indicate that  IC7610 does not rely on ALC as a means of compression like  many Icom radio models which was responsible  for the horrendous wide band splatter that was so common on Icom radios. The Icom 7800 suffered from this issue as well.

Most users that I have heard are not overly impressed or have not mentioned 1 killer feature that makes the radio  an exceptional  radio. The praise seems very muted because many of the new IC7610 users seem to have owned a IC7300 before hand. The Icom IC7300 radio for the money I think has left many users wondering what they paid extra for. Thats  just what I am sensing from users since the praise is rather muted and the praise not as forthcoming as that of the IC7700 and IC7800 when these radios were release. I could be 100% wrong in my anecdotal observations.

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VK3BL
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« Reply #4 on: November 21, 2017, 01:45:11 AM »

Dear Zenki,

Please don't take my transmitted signal to date as indicative of TX IMD performance; my THP-2.5Kfx was in the shop, so I was relying on my 12v (albeit at 15v) THP-450B to make ~350 watts.

I'll definitely check the TX IMD.  I've found in the past Icom's as a general rule are "wide" when used to tx 100-2900.

2 tone I'm not as interested so much as I am averaged FFT SSB; I believe it gives a more accurate representation of real world conditions.

That said, I'm expecting something in the order of ~-30dB down IMD3, although there is a 'drive' control so perhaps it may be possible to bias it closer to class A.

I'll let you know,

Cheers,

Jarrad VK3BL
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J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
W6UV
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« Reply #5 on: November 21, 2017, 07:09:41 AM »

How well does the 7610 hear on the LW and MW broadcast bands?

Does it have SAM mode (synchronous AM)? I didn't see it mentioned in the manual.
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VK3BL
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« Reply #6 on: November 22, 2017, 07:15:28 PM »

How well does the 7610 hear on the LW and MW broadcast bands?

Does it have SAM mode (synchronous AM)? I didn't see it mentioned in the manual.


I don't believe it does.  One strange thing on the other hand is it offers synchronous CW and SSB; I'm not sure how that works exactly, but I have it turned on and have no complaints.

I'll definitely do some MW Broadcast band stuff; I'll post the raw audio recorded straight from the radio, as well as the output converted with a baseband ADC aka soundcard.

Thanks very much for the idea!  More videos to come on the weekend - get your requests in guys! Smiley
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J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
VK3BL
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« Reply #7 on: November 26, 2017, 11:51:19 PM »

How well does the 7610 hear on the LW and MW broadcast bands?

Does it have SAM mode (synchronous AM)? I didn't see it mentioned in the manual.


It doesn't have SAM for AM, at least not in the initial firmware, but it hears VERY VERY well on the MW band; it is much more sensitive than the IC-7300.

Unlike the IC-7300, you have to master the use of Attenuation and RF Gain knob if you have a good antenna system; a dipole up 14M is enough to overload it in my shack without doing the former.

That said, its easy to tame (sensitivity isn't a bad thing), and offers better audio quality than the IC-7300; the bass response is much more natural.

Check out my latest video comparing the two.  Its only an audio track, but with a good set of headphones or speakers you will hear the difference between them.  The last part of the audio track features each radio on a separate channel, so you can run your own frequency response analysis if desired Smiley

I'll cover setting the radio up for strong signal MW use in the future Smiley

73, Jarrad
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J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
AC7CW
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« Reply #8 on: November 27, 2017, 09:16:48 AM »

One strange thing on the other hand is it offers synchronous CW and SSB; I'm not sure how that works exactly, but I have it turned on and have no complaints.

Curious, that. With a normal product detector CW and SSB are by nature synchronously detected, no?  I wonder how much difference that could make.
« Last Edit: November 27, 2017, 09:19:17 AM by AC7CW » Logged

Novice 1958, 20WPM Extra now... (and get off my lawn)
KE2TR
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« Reply #9 on: November 28, 2017, 09:39:32 AM »

To ZENKI, let me get this strait you want to use a cheap SDR receiver as a spectrum analyzer to test the IMD products??? You have got to be kidding us all with all your posts about IMD and stuff you want this fellow to use an un calibrated RX instead of a real calibrated spectrum analyzer to look if there is any IMD. First off I have know idea if you are even have an amateur call or with all your IMD statements if you really know how these thing are tested but I can tell you for sure they dont use some cheap SDR receiver for any tests at all and for that matter no SDR receiver is used to really test 3rd ot 5th order IMD tests in any lab, you have got to be frigging kidding all of us on these forums with your ranting and raving of IMD cause most of the time on the ham bands today those by products are a product of NOT RTFM (reading the frigging manual) and the mic or processors knobs are all the way to the right, over driving a SS amp or into a hi SWR, tube amps over driven or not properly loaded. All of these thing will cause un real IMD, I have seen a guy on 75m in the morning who no matter what radio he is on and he has a few is always 5-7Khz wide cause he is pinning his alc meter and this is without any amp in line, pure and simple he does not use any metering on his radio or does not care, all knobs to the right. Over driving these new SS amp's is becoming another issue cause many of them do not need 100w to drive plus some only need 25w for full output and many of the tube amp's dont really give you a proper manual as far as tuning your amp up for proper output. The use of many new amp companies which incorporate tetrode designs do not have fail safe's built in like the Acom amp's who have these features built in them since the late 1990ies plus Acom goes a step further in there manuals to state that distortion products can arise if not properly tuned.
If the 7610 is any thing like the 7300 as far as its output section and the way the transmit audio is generated I am sure that the IMD products are about the same which is not bad by today's standards which correct me if I am wrong but the 7300 3rd order was tested at 38db down and only on 10 meters it dropped down to 30db, it may not be as low as the Anan radio's with 45db down 3rd order but for today's radio's 38db is not to shabby.
Clearly ZENKI has no clue to his ranting and raving about IMD and transmitter distortion and if he did he would know that it is up to the stations operator who sets his gain controls up that controls how good or bad the IMD is no mater how well a radio does in a lab test there is know governors in place that limit improper setting of the controls, any radio can be pushed to an undesirable limit plus all these aftermarket TX audio add on devices do not help they just cause more problems and 9 times out of ten add more distortion to the signal, keep it simple keep it clean...
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VK3BL
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« Reply #10 on: November 29, 2017, 12:01:48 AM »

IMD is such a loaded topic. 

I have personally measured my ANAN 100D at -55 IMD3 with the SDR Play (which is actually pretty decently calibrated), but had a friend down the road report my 'real' IMD3 as -30.

Why? Distortion was being generated in either his antenna system or my own.

I found evidence of intermittent arcing in an N Connector used outside, and promptly replaced it; the fact of the matter is I intend to move to 7/16 DIN for outdoor use when any length of coax feed line is subject to a vSWR above 5:1; it is very easy to overlook the fact that voice peaks in SSB can generate very high voltages on a transmission line, even if the loss is not worth worrying about due to the length.

In my case, I was feeding ladder line with a 10 ft section of LDF-450; I couldn't care less about the loss, but the vSWR was enough to intermittently cause arcing at the balun junction point N connector. 

Even at 400 Watts PEP on a 50 ohm line, a 1:1 vSWR will result in peaks of 141 volts.  Multiply this by 5 (vSWR 5:1), and you have 700 volt peaks; its easy to see how a dirty, broken, slightly wet or frankly cheap connector can cause rectification via arcing.

QRO and insufficient / poor choice of connectors should get equally as much attention in 'all knobs to the right' syndrome, IMHO.

On another occasion my 'monitoring receiver' was reporting an IMD3 of -20.  I tore my antenna system apart looking for a fault, only to find that the antenna attached to the SMA connector on the SDR Play had come loose... The second I tightened it back up, everything was rosy. 

There is a reason professional grade connector manufacturers offer specification sheets and torque calibrated tools.

We hams need to start paying attention to these things if we want to put out clean signals at high power; rather than just assuming 'all knobs are to the right' or 'tetrodes are always dirty'.  We can and should help each other.

The first thing we should start doing is STOP dropping the v from vSWR.

« Last Edit: November 29, 2017, 12:14:58 AM by VK3BL » Logged

J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
W6UV
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« Reply #11 on: November 29, 2017, 10:39:19 AM »

How well does the 7610 play on CW, specifically QSK?
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K6BRN
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« Reply #12 on: December 10, 2017, 10:27:52 AM »

James (KE2TR):

I agree, "Zenki" (who seems to have some sort of IMD obsessive compulsive disorder) and most of the IMD hysteria is out to lunch.  (Not ALL of it... some amps ARE pretty bad, as well as SOME tranceivers)

Part of the humor in this is that as transmitter/amp IMD drops below -30dbc, passive intermodulation distortion becomes a significant contributor, and it is generated entirely in the antenna and signal distribution system.  The more connectors and other passive devices in the string and the more corrosion on them and between them, the worse PIM is.  This is a major problem in commercial cellular and microwave relay comms systems, where a great deal of design effort is dedicated to minimizing it.

How many hams are PIM-aware?  Certainly not Zenki, because its NEVER come up.  So when I hear his grand rants on IMD levels of -50db and better, I simply shake my head.

Another contributor to apparent IMD that is becoming very common is overload in the front end (sample and hold and ADC) of digital signal processing receivers.  This happens in the SDRplay, IC-7300 a even in sound cards when running digital modes.    The latter is most obvious when mixing products from RX overload causes a strong signal to be duplicated multiple times when running digital modes.

Most users simply do not know how to deal with this and blame the TX source rather than their own RX settings.  This is very relevant to the IC-7610, as was mentioned above, because it can easily overload and front end loading must be managed using RF gain and attenuator/pre-amp controls.  Probably why Icom felt it VERY necessary to include preselector filtering in the IC-7610.

Brian - K6BRN
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VK3BL
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« Reply #13 on: December 10, 2017, 03:35:24 PM »

Fantastic post Brian; so many people don't consider PIM at HF, or even how well shielded their shack is from their antennas.

There is much more to putting out a clean signal than a transceiver's IMD or an amps.
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J.D. Mitchell - VK3BL / XU7AGA - http://vk3bl.wordpress.com
KA4DPO
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« Reply #14 on: December 11, 2017, 09:24:12 AM »

James (KE2TR):

I agree, "Zenki" (who seems to have some sort of IMD obsessive compulsive disorder) and most of the IMD hysteria is out to lunch.  (Not ALL of it... some amps ARE pretty bad, as well as SOME tranceivers)

Part of the humor in this is that as transmitter/amp IMD drops below -30dbc, passive intermodulation distortion becomes a significant contributor, and it is generated entirely in the antenna and signal distribution system.  The more connectors and other passive devices in the string and the more corrosion on them and between them, the worse PIM is.  This is a major problem in commercial cellular and microwave relay comms systems, where a great deal of design effort is dedicated to minimizing it.

How many hams are PIM-aware?  Certainly not Zenki, because its NEVER come up.  So when I hear his grand rants on IMD levels of -50db and better, I simply shake my head.

Another contributor to apparent IMD that is becoming very common is overload in the front end (sample and hold and ADC) of digital signal processing receivers.  This happens in the SDRplay, IC-7300 a even in sound cards when running digital modes.    The latter is most obvious when mixing products from RX overload causes a strong signal to be duplicated multiple times when running digital modes.

Most users simply do not know how to deal with this and blame the TX source rather than their own RX settings.  This is very relevant to the IC-7610, as was mentioned above, because it can easily overload and front end loading must be managed using RF gain and attenuator/pre-amp controls.  Probably why Icom felt it VERY necessary to include preselector filtering in the IC-7610.

Brian - K6BRN

Well said Brian.  Unfortunately we are in the era of plug and play amateur radio.  Far too many new amateurs don't understand the importance of maximizing system efficiency and they don't understand that the feedline, antenna, and all of the connectors are part of the system.  As for reducing RF gain, that is another issue that seems to escape a lot of new hams.  There is an RF gain control on the radio for a reason, if there was no need to change it there would not be a knob on the front panel.  Hopefully some of the new amateurs will read this thread and learn something.
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