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So the whole AM modulation issue is unresolved?


 

Well wit a discontinued radio it won't be resolved by Icom, but what is the issue?


D C *Mac* Macdonald
 

What, exactly, is the ISSUE?  Virtually all current SSB/CW rigs
specify that AM carrier should be set at approximately 1/4 of
the SSB PEP rating.  100% AM modulation of a 25 Watt carrier
develops 100 Watts of PEP energy.   Simple enough!
 
73 - Mac, K2GKK/5
Since 30 Nov 1953
Oklahoma City, OK
USAF (Retired) 61-81
FAA (Retired) 94-10


From: ic7000@groups.io <ic7000@groups.io> on behalf of J.D. Barron <jeter.d.barron@...>
Sent: Saturday, August 15, 2020 07:26
To: ic7000@groups.io <ic7000@groups.io>
Subject: Re: [ic7000] So the whole AM modulation issue is unresolved?
 
Well wit a discontinued radio it won't be resolved by Icom, but what is the issue?


Helmut Wabnig
 

On Sat, 15 Aug 2020 17:36:32 +0000, you wrote:

What, exactly, is the ISSUE? Virtually all current SSB/CW rigs
specify that AM carrier should be set at approximately 1/4 of
the SSB PEP rating. 100% AM modulation of a 25 Watt carrier
develops 100 Watts of PEP energy. Simple enough!

73 - Mac, K2GKK/5
Since 30 Nov 1953
Oklahoma City, OK
USAF (Retired) 61-81
FAA (Retired) 94-10
Still I don't know what's the issue with the 7000 :-)

OE8UWW


 

So this unresolved problem is undefined and unnecessary as an operational issue?
It takes a little time for the ALC to cut back the carrier power to the proper level, but then it is probably unmodulated at that time so the peak envelope power is still within limits.
So this is a problem looking for a problem?


D C *Mac* Macdonald
 

I concur that this apparent initial spike is probably limited
by ALC to a value that will NOT cause a problem since it is
a momentary (and safe) level.  An unreal problem in search
of a solution, indeed.
 
73 - Mac, K2GKK/5
Since 30 Nov 1953
Oklahoma City, OK
USAF (Retired) 61-81
FAA (Retired) 94-10


From: ic7000@groups.io <ic7000@groups.io> on behalf of J.D. Barron <jeter.d.barron@...>
Sent: Sunday, August 16, 2020 08:33
To: ic7000@groups.io <ic7000@groups.io>
Subject: Re: [ic7000] So the whole AM modulation issue is unresolved?
 
So this unresolved problem is undefined and unnecessary as an operational issue?
It takes a little time for the ALC to cut back the carrier power to the proper level, but then it is probably unmodulated at that time so the peak envelope power is still within limits.
So this is a problem looking for a problem?
_


 

I still fail to understand what the issue with AM is. For a SSB radio with AM as really an after thought and with it providing all of the power that the finals can safely handle what are you looking for? 
Did you want the IC7000 to work like a Johnson Ranger with a 6146 modulated by a pair of 6L6s?
The Ranger was discontinued in about 60 years ago.
So far no one has stated what the issue to be resolved is.
And no Icom will not be investigating and fixing whatever the perceived problem might be when the IC7000 has been discontinued for six years and many parts are NLA.
I sold my last one because parts were getting harder to find and support is limited, well that and the IC7300.


rich bassett
 

I don't think anybody really cares about  the 7000 AM unless your using it on 11 meters.   It is not a good radio for am, so forget about it.  Being a ham now for over 50 years, AM is just a side case hobby for hams to use old wonder radios from the 50 and 60s.    I hear these guys go lock to talk for 10 minutes at a time on 75 meters  with nobody really caring what the other guy has said. The little ICOM can not stand that kind of duty cycle.  BTW, I think you mean " a bunch of crazy people ".  

On Sunday, August 16, 2020, 9:12:12 AM PDT, sezfamily via groups.io <sezfamily@...> wrote:


Well in reading past posts on this forum it has been concluded that AM is controlled by software and in no way is allowed to provide any reasonable peak that even comes close to 4:1.  Mic gain, mic mods seem to provide no relief.  Would be nice if a simple 25 to 100 would work but it is said its impossible on the 7000 due to DSP not allowing for it.  Or all the past posts on this forum from a bunch or crazy people? 


Steve W3AHL
 

When Compression is on more than just a little it causes the PTT switch "click" in the mic to be amplified.  If you turn Compression off or use a foot switch the spike goes away.  There can be other causes of the initial spike, but this is the most common and easily dianogosed.  It can cause problems on some solid state amplifiers, causing them to fault due to too much drive.

For scope traces showing the problem, see my document in the files area of this group:  https://groups.io/g/ic7000/files/7K%20PTT%20Spike%20with%20Compression.doc
I tried to delete the .doc file and replace it with a PDF version, but for some reason I could do neither.  Seems to be a problem with the Files interface.  Will try later....

Steve, W3AHL


 

Thanks for the insight, Steve. That makes sense. I have never seen this spike since I don't run much compression as most of what I did was digital where linearity is important.
As with many issues with the IC7000 it is self inflicted or imaginary.
I had three IC7000s and sold them mostly because I am getting where replacing parts the size of a grain of salt is getting harder.
A great radio that I replaced with another great radio, the IC7300.
A lot of the issues come from just a few people, just saying.


Simon Thompson
 

Is it possible for the moderator of this group to remove Paul from its membership? I am tired of his semi-literate personal attacks against other group members, particularly against long-time forum members who have a great deal of sound technical expertise with the ic 7000 on which the group draws.


 

I agree with Simon 100%


 

Forum not worth the hassle with Paul's idiocy so to make him and me happy I am leaving.
The remaining users can put up with him.
He cannot be helped, Cannot be taught manners, and is basically a spoiler with nothing to contribute.
Everyone have a great day
Bye.


Simon Thompson
 

This is exactly why trolls should not be tolerated; knowledgeable folks with better things to do refuse to tolerate nonsense, and vote with their feet, and the race to the bottom starts. Eventually, the forum is abandoned by users who can, in fact, provide resources, and is taken over by users who can only offer loud, uninformed and obnoxious noise.

On Mon, Aug 17, 2020 at 4:32 PM J.D. Barron <jeter.d.barron@...> wrote:
Forum not worth the hassle with Paul's idiocy so to make him and me happy I am leaving.
The remaining users can put up with him.
He cannot be helped, Cannot be taught manners, and is basically a spoiler with nothing to contribute.
Everyone have a great day
Bye.








Max
 

Enough already !

On Monday, August 17, 2020, 06:11:06 PM CDT, Paul <pg321@...> wrote:


I'm waiting also btw , i enjoy the 1 sided "account" on who does what , as if i have annoyed you so much to name it semi-illiterate how come one seems to "understand" everything that is typed hypocrite , it very well could be possible ! , sincerely Paul .

ps- it even agrees .


Steve W3AHL
 

Paul,

Normally I would have fired up a 7K to look at the problem in AM mode, which I never use.  But I'm in the process of moving to NM, which has been complicated by the pandemic, so most radio stuff is there or here in NC in moving boxes.  No I'm not an idiot.  Yes I do use the two 7K's still, primarily mobile SSB HF and Pactor digital.  And I never engage in personal attacks on forum members.  We all have our own stories behind our questions, problems and answers, which are hard to appreciate when all you see is a brief post on a forum, without knowing the person or his experinece level.

Your attitude could use some toning down, but I hope you continue to contribute to the group, since many of the original 7K owners have moved on or passed on.  I rarely post anymore since most of my air time is with Elecraft rigs and I now own a robotic astronomy observatory on a mountain top in NM, which cuts into my free time and sleep time a lot....

Steve, W3AHL


wgsmith2k@...
 

Steve,

Is your observatory anywhere near Spot, NM?  I used to occasionally visit that observatory years ago when I lived in southern NM.

73!
Winston, N4WFB


Steve W3AHL
 

Hi Winston,

Perhaps you mean Sunspot, NM?  Mine is about 32 miles north, then east on Hwy 82, or 15 miles east of Cloudcroft.  It's in one of two amateur astronomy communities in that area, plus a rent-a-dome, rent-a-scope facility also.  Elevation is 7200'.

Steve, W3AHL


Gene Horr
 

> You believe that AM is only used on 11 meters..? 

For mobiles rigs…yes?

 


 

The best thing for people who want to use a really good SSB mobile transceiver for more than just an OK it will do AM rig is to buy something that will make them happy. 
If the idea is to work on having HiFi AM for 80 meter ragchewing then perhaps a different radio is for you.
Icom will never rework the firmware to make an auxiliary function work like you might like it to. 
There is no information in the carrier so why transmit it in this age where we have such stable oscillators?
Why transmit the same data twice once in the upper and also in the lower?
The IC7000 is a modern transceiver that offers AM as an after thought that is possible, but not a priority. 
Possible a better solution to AM on an SSB transceiver would be to just reinsert a carrier with only enough amplitude to demodulate the sideband.
If someone has looked at the signal on a spectrum analyzer made sure that is not what they do? It would be much easier than lots of other methods.
I remember we used to turn the modulation all the way down on the Collins S line and get about 3 watts of AM with one sideband. 
Perhaps the applicability of AM would be for emergency communications on VHF aircraft band which is AM (not to mention CB). Most other services these days are either FM or SSB (perhaps digital as wall). Most probably the AM mode is included more for receive than transmitting.
I think AM for this radio is more of an afterthought than a really big feature. 
I think I will take a look at my IC7300 on my FM/AM 1200S to see what the AM looks like, just out of curiosity.
That will probably be the only time the AM function is used for transmit on that box


Doug Neal
 


Gentlemen/Ladies
The whole AM issue on SSB radios is just there for a convenience. if you want  to run AM get a rig designed to do it. I have an old Heathkit pair Apachie/Mohawk set aside for AM just in case I ever feel the need. You can't beat plate modulated AM.  If that's your bag.
BTW: CB sports a whole bunch of SSB radios, CBers have been using SSB for years. 
What I can't understand is why the aircraft industry still uses AM. I would think FM would be used in this day and age. Anyone know the answer?
Thanks for reading.
73 ,
Doug 



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