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Author Topic: AM mode on IC7610 compared to IC7600. Why? Solution?  (Read 373 times)

N2RRA

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AM mode on IC7610 compared to IC7600. Why? Solution?
« on: March 13, 2021, 06:20:17 AM »

I decided to play in the AM QSO Party Contest this weekend 3/13 to 3/14/21 with hopes we can enjoy the mode and promote using this mode a bit more. Any transceiver qualifies for this contest and while some think their rig may not do so well they don’t know cause they either never tried, or have given it enough of a run.

My ic7600 had some great hi-fi amplitude modulation (AM) when I used it last reported by hard core am guys on 80 meters. They didn’t even know I was on a IC7600 till I mentioned it. Problem I’m having now is I can not get my IC7610 to sound the same. Using the same mic 🎤 and everything else I notice on the O-scope I seem to be only getting 200-3000 kHz of TBW where as my Ic7600 was producing 100-3000 kHz TBW showing on the O-scope. That’s only what I can see cause I was told it sounded slightly wider than that given the proper EQ’ing I had on it. I was even sent an audio file recording via email and sounded amazing. Just not getting at all the same low frequency on the IC7610.

Now, I did go into the menu settings and had the bass and treble adjusted on the IC7610 so it’s not that.

Is anyone else having this problem with their IC7610?

Eric
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K0UA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #1 on: March 13, 2021, 08:10:36 AM »

I decided to play in the AM QSO Party Contest this weekend 3/13 to 3/14/21 with hopes we can enjoy the mode and promote using this mode a bit more. Any transceiver qualifies for this contest and while some think their rig may not do so well they don’t know cause they either never tried, or have given it enough of a run.

My ic7600 had some great hi-fi amplitude modulation (AM) when I used it last reported by hard core am guys on 80 meters. They didn’t even know I was on a IC7600 till I mentioned it. Problem I’m having now is I can not get my IC7610 to sound the same. Using the same mic 🎤 and everything else I notice on the O-scope I seem to be only getting 200-3000 kHz of TBW where as my Ic7600 was producing 100-3000 kHz TBW showing on the O-scope. That’s only what I can see cause I was told it sounded slightly wider than that given the proper EQ’ing I had on it. I was even sent an audio file recording via email and sounded amazing. Just not getting at all the same low frequency on the IC7610.

Now, I did go into the menu settings and had the bass and treble adjusted on the IC7610 so it’s not that.

Is anyone else having this problem with their IC7610?

Eric

Go ask Bob Heil. From what I understand he was instrumental in the development of the 7300 and 7610 audio. I think he had them remove anything below 200 hz.  Watch this video below.

https://www.youtube.com/watch?v=BuD-4hN9hFQ
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73  James K0UA

N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #2 on: March 13, 2021, 09:55:47 AM »

I decided to play in the AM QSO Party Contest this weekend 3/13 to 3/14/21 with hopes we can enjoy the mode and promote using this mode a bit more. Any transceiver qualifies for this contest and while some think their rig may not do so well they don’t know cause they either never tried, or have given it enough of a run.

My ic7600 had some great hi-fi amplitude modulation (AM) when I used it last reported by hard core am guys on 80 meters. They didn’t even know I was on a IC7600 till I mentioned it. Problem I’m having now is I can not get my IC7610 to sound the same. Using the same mic 🎤 and everything else I notice on the O-scope I seem to be only getting 200-3000 kHz of TBW where as my Ic7600 was producing 100-3000 kHz TBW showing on the O-scope. That’s only what I can see cause I was told it sounded slightly wider than that given the proper EQ’ing I had on it. I was even sent an audio file recording via email and sounded amazing. Just not getting at all the same low frequency on the IC7610.

Now, I did go into the menu settings and had the bass and treble adjusted on the IC7610 so it’s not that.

Is anyone else having this problem with their IC7610?

Eric

Go ask Bob Heil. From what I understand he was instrumental in the development of the 7300 and 7610 audio. I think he had them remove anything below 200 hz.  Watch this video below.

https://www.youtube.com/watch?v=BuD-4hN9hFQ

Well, that would be just dumb if so. I watched the video and he mentions something about rolling off at 160hz.

Guess I could ask him, but also be nice to hear what others have experienced. While I shoot Heil an email to ask the question let’s see if it’s just my IC7610. It is an SDR and mines could be corrupt. All I know is my IC7600 AM audio blows away the IC7610 and if that’s Heil’s fault then I won’t be a happy camper. LOL

I’m sorry, I’m just not the jump on the band wagon type.
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K6AER

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #3 on: March 13, 2021, 10:24:28 AM »

Did you do a master re-boot to see if that solves the problem?
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N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #4 on: March 13, 2021, 11:05:16 AM »

Did you do a master re-boot to see if that solves the problem?

Very good question.

When I initially bought the radio from HRO the very same day I placed it on the air and was getting horrible reports. Reports like RFI on the audio and some sort of distortion. I jumped on a remote SDR receiver located 500 miles away to listen to my audio and sure enough verified the reports. By the third day checking everything I placed it right back in the box to take right back to HRO, but a day later something told me to pull it back out and find the problem.

Someone suggested a hard reset of the radio and BOOM. Finally, the radio was sounding much better. It’s been getting pretty good reports since then. I since done it a second time just for the hell of it sometime back, but seemed to didn’t need it as the transmitted audio on SSB still sounds great.

Answer would be yes. Could 🤷🏼‍♂️ it still be the firmware and isolated to my 7610?

That’s the AM golden question.
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K0UA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #5 on: March 13, 2021, 01:26:39 PM »

If I had a $100 I would lay it down and bet,,,no, there is nothing wrong with your firmware (are you on 1.20?)  But I don't  :) 
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73  James K0UA

N2DTS

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #6 on: March 13, 2021, 03:20:33 PM »

The 7300's I had went to 100 Hz TX I think, at least that is what the menu said.
My problem with the radio was RX was limited to 200 Hz as the lowest it would pass.
I would like it to be there to hear, other sdr radios allow down to 20 Hz which is cool into the Marantz audio amp and bit 3 way speaker.
Its nice if it can do it, you can always cut it, but you cant have it if its not there.
The 7300 and 7610 are he first Icom radios that make AM well (the modulation).
The older radios had serious ALC issues with the AM mode.

I would own a 7610 if the audio sounded good, but it does not.
It would also be nice if the high end went to at least 3500 Hz but I dont TX AM at 25 watts so its not important to me.
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N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #7 on: March 13, 2021, 06:06:55 PM »

The 7300's I had went to 100 Hz TX I think, at least that is what the menu said.
My problem with the radio was RX was limited to 200 Hz as the lowest it would pass.
I would like it to be there to hear, other sdr radios allow down to 20 Hz which is cool into the Marantz audio amp and bit 3 way speaker.
Its nice if it can do it, you can always cut it, but you cant have it if its not there.
The 7300 and 7610 are he first Icom radios that make AM well (the modulation).
The older radios had serious ALC issues with the AM mode.

I would own a 7610 if the audio sounded good, but it does not.
It would also be nice if the high end went to at least 3500 Hz but I dont TX AM at 25 watts so its not important to me.

That’s interesting cause I’ve been able to make all my Icom’s sound fantastic on SSB and better than most even as far back as the IC751A. The IC775DSP sounded great, but the original IC756 had great audio. My IC7610 now sounds as good as any Yeasu or Kenwood, but nothing beats a Kenwood, or Anan rig. Not even a Flex.

That being said, if you read the thread I had my IC7600 on AM sounding incredible. Still have the audio file recording taken from a Flex. Proof is in the pudding.

Now only if I could get the IC7610 to sound like it on AM. 
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N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #8 on: March 13, 2021, 06:08:34 PM »

If I had a $100 I would lay it down and bet,,,no, there is nothing wrong with your firmware (are you on 1.20?)  But I don't  :)

Well, something is definitely wrong cause comparing the audio in my IC7610 to my IC7600 it’s hard to believe they’re the same manufacturer.
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N2DTS

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #9 on: March 15, 2021, 01:49:54 PM »

Sure they sound good on ssb, but on AM they had issues with the audio (modulation) triggering the alc and closing down the carrier which sounded nasty.
Some guys were using a 9 volt battery and a pot into the alc port to prevent that but I think you had to disable the ALC with an adjustment and set it manaully with the pot.
All the 756 pro series were like that, the 735 I had you could adjust a pot inside the radio to prevent it but then the radio could TX over 100 watts, even to 200 watts so it was not a good idea.
The 7300 was the first Icom I have heard of that modulated fully and cleanly out of the box, just with a narrow bandwidth...

The radios should be able to do 25 watts carrier and 100 watts pep without hitting the alc.
That is 100% modulation.
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N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #10 on: March 15, 2021, 04:23:42 PM »

Sure they sound good on ssb, but on AM they had issues with the audio (modulation) triggering the alc and closing down the carrier which sounded nasty.
Some guys were using a 9 volt battery and a pot into the alc port to prevent that but I think you had to disable the ALC with an adjustment and set it manaully with the pot.
All the 756 pro series were like that, the 735 I had you could adjust a pot inside the radio to prevent it but then the radio could TX over 100 watts, even to 200 watts so it was not a good idea.
The 7300 was the first Icom I have heard of that modulated fully and cleanly out of the box, just with a narrow bandwidth...

The radios should be able to do 25 watts carrier and 100 watts pep without hitting the alc.
That is 100% modulation.

All very good valuable information, but information I am also aware of. The thing is I don’t think they were the same with all units for some reason. On a.m. I was able to get one of my 756 pro threes to sound pretty damn good on a.m. without the mid to narrow band with. I still have the audio recording that was done via a flex SDR receiver and Verifies the same identical reports I was getting from the A.M.ers at the time. They weren’t even aware that I was on a solid-state rig. It had all the low frequency, mid and high’s that you would want in an a.m. signal. I think I’m going to upload it to my YouTube channel to use as an example of how you can get a IC7600 to sound great on a.m. It sounded absolutely fantastic. That was with my IC7600 running my alpha 86 amplifier. The question is despite your information it does not correlate with why I was able to get a 756 pro three and a 7600 to sound absolutely incredible with all the fundamentals in a AM signal you would want and can’t duplicate it now with my 7610. If I could upload the audio recording to this forum I would and that would really put a lot of your claims and my claims to rest.

I’ll upload the recording tonight onto my YouTube channel as an example of what a ic7600 on AM could sound like.
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N2DTS

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #11 on: March 15, 2021, 05:14:00 PM »

Maybe it depends on what you thing sounds 'good'.

Most AM operators would say 40 to 5000 Hz with low distortion and multi band processing sounds good.
Many use full broadcast setups, and many are broadcast engineers.
Some of the radios in use are actually better then old broadcast transmitters, class D and E rigs and the good sdr radios like the Anan and Flex radios that can transmit 20 Hz in a clean sine wave.

For me, I like audio from 20 to 3000 Hz without excessive low end boost and a nice rise around 1000 Hz,
 and low distortion. I can not hear anything above 3000 Hz so that hifi stuff does nothing for me.

Many think the 7300 sounds thin and grungy on TX but it sounds ok to me.
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N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #12 on: March 15, 2021, 09:07:58 PM »

Maybe it depends on what you thing sounds 'good'.

Most AM operators would say 40 to 5000 Hz with low distortion and multi band processing sounds good.
Many use full broadcast setups, and many are broadcast engineers.
Some of the radios in use are actually better then old broadcast transmitters, class D and E rigs and the good sdr radios like the Anan and Flex radios that can transmit 20 Hz in a clean sine wave.

For me, I like audio from 20 to 3000 Hz without excessive low end boost and a nice rise around 1000 Hz,
 and low distortion. I can not hear anything above 3000 Hz so that hifi stuff does nothing for me.

Many think the 7300 sounds thin and grungy on TX but it sounds ok to me.

Maybe you’re trying so hard to convince us and prove your point you’ve been trying to make about Icoms sounding like crap that you keep either missing the point, or not acknowledging the specifics I’ve already pointed out distinguishing the difference in effect I’ve clearly stated between the IC7610 and my prior IC7600. So let me put it maybe in a more laymen’s terms.

Icom 7600 sounded “good” on AM with a full 100hz (slightly lower) to 3000khz (slightly higher).

Icom 7610 sounding “bad” on AM with a low cut of around 200hz to 3000khz.

So forget about the old Icoms of 30 years ago, or the Icom’s of 20 years ago I was able to sound great on AM. Let’s cover why am I having this problem with a modern SDR rig that should sound as good if not better than my IC7600. Why, or why not and who’s fault would that be?

It surly isn’t my fault cause despite you second guessing my knowledge, or competence on audio you should find out first about my successes with audio. An audio engineer label has taught me not one thing. I’ve heard audio engineers get it all wrong on the air.

So do you have something to substantiate the reason why maybe there would be a problem and how to fix it, or at least a hypothetical?

That does not have anything to do with old radios, or basic common knowledge I and others already possess.

Thank you.
« Last Edit: March 15, 2021, 09:13:32 PM by N2RRA »
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N2DTS

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #13 on: March 16, 2021, 02:23:18 PM »

I never had a 7600 or heard one on AM, I thought it was a warmed over 756 pro3.
A lot of people think the 7300 sounds good on AM TX.
The 7610 uses the same setup I would think, so why does it not sound good?
Is it you who things it does not sound good, or do you get reports it does not sound good?

Many AM'ers would say nothing that does 100 to 3000 sounds good.
I am not one of them. It can sound good to me since that is as high as I can hear.
200 to 3000 is just less low end, and 200 Hz is close to the 'mud' frequencies so don't boost the lows.
Many AM,ers cut around 220 Hz and boost well below that.
With very limited frequency response of the transmitter, there is little you can do with the tone
controls Icom gives you.



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N2RRA

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Re: AM mode on IC7610 compared to IC7600. Why? Solution?
« Reply #14 on: March 16, 2021, 03:48:23 PM »

I never had a 7600 or heard one on AM, I thought it was a warmed over 756 pro3.
A lot of people think the 7300 sounds good on AM TX.
The 7610 uses the same setup I would think, so why does it not sound good?
Is it you who things it does not sound good, or do you get reports it does not sound good?

Many AM'ers would say nothing that does 100 to 3000 sounds good.
I am not one of them. It can sound good to me since that is as high as I can hear.
200 to 3000 is just less low end, and 200 Hz is close to the 'mud' frequencies so don't boost the lows.
Many AM,ers cut around 220 Hz and boost well below that.
With very limited frequency response of the transmitter, there is little you can do with the tone
controls Icom gives you.

That’s the thing. You can’t assume, or go by what you’ve read about some thing. You should have some experience with the equipment. That’s why your unsure of things which doesn’t help the conversation.

ICOM rigs from the 775DSP, 756, 756pro up to the IC7600 pretty much shared the same 2.8-2.9khz tonal quality of audio. The exceptions were tone/base controls and TBW adjustment down the road, but each fixed setting pretty much were the same. I even got a IC751A to sound great cause they will produce 2.8khz of tbw with right filter in it. So the differences were subtle cause most guys put EQ’s on them over the years and then you couldn’t tell. They could all made to sound equivalent. Forward to the 7300 and 7610 and its a total different animal in audio circuit.

I haven’t heard a 7300, or 7610 on air yet which next time I cross someone with one I am going to ask to shift to AM to see. Take a few experiences and make a proper assessment at what they sound like with and with out external EQ if I can compile enough variant QSO’s and data.

Based on my vast experience with audio over the years and ICOM rigs I’m well aware of what one should and could sound like. I posted a short video on my YouTube channel so you could hear the AM signal. That was a receiver listening at 6khz through a Flex 6400.

Wondering what it should sound like? Now you can hear for yourself and make sure you don’t use cheap headphones, or cheap speakers. Use a good set of headphones, or at least a set of speakers that have both bass, mids and highs.

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