AM Modulation Monitor Designed for US!

[steve_qix]

A Modulation Monitor designed for the AM Community!

This is a peak reading instrument, showing your true modulation percentage
at all times.

The monitor features separate high resolution (100 LEDs total)
positive and negative peak meters, and both meters include a peak-hold function.

An adjustable negative peak flasher is also included.

Unlike most commercial modulation monitors, the AMM-HF1 will accurately display modulation
levels up to 150% positive, a modulation level achieved by many good-quality amateur transmitters.



Click on picture or here to view larger image

For more information, including a complete list of features, check the Radio Engineering Associates' Web Site

Regards,

Steve

[Blaine N1GTU]

can i place an order?
must have for my shack, and i have the perfect spot in the rack waiting for it.
very cool product.

ps: I made your post a sticky so it stays at the top

[K1JJ]

Looks like a well thought and useful unit, Steve.

I'd be interested in one too.  When is delivery and how much?

It will be a nice companion next to the scope for total monitoring capability.


T

[steve_qix]

Looks like a well thought and useful unit, Steve.

I'd be interested in one too.  When is delivery and how much?

It will be a nice companion next to the scope for total monitoring capability.


T

Hi Tom!

Pricing and delivery info are on the Radio Engineering Associates web site :-)

[W1UX]

fantastic Steve. A really useful display! Look forward to its distribution to us peasants out in the field
73 and nice to hear about it on the air the other day, too.
Al UX

[Steve - WB3HUZ]

Looks cool! But with all due respect, a $5 scope will give you much more useful information, and it isn't limited to a measly 150% modulation.

[steve_qix]

Looks cool! But with all due respect, a $5 scope will give you much more useful information, and it isn't limited to a measly 150% modulation.

Hey Steve,

Well, I don't know about that :-).  Unless you have a very modern (and expensive) 'scope, you won't have peak hold; you won't have a quantitative measure of your modulation.  You can't measure carrier shift and there's no audio output.  You can definitely *estimate*, and sometimes I find looking at the waveshape useful.

But, like most things, it's subjective   Makes the world go 'round.

Talk later and Regards,

Steve

[Steve - WB3HUZ]

All true to an extent. I can see EVERY peak on the scope. No need for peak hold. I can measure percentage rather closely, not that it's a big deal to me. I just want to be as close to 100% without going over on the negative peaks - all easily seen on the scope. I will not only have a quantitative measure, but a qualitative one too - I can see any hum, some distortions, oscillations, or other non-voice modulation of the carrier. In fact, over time, I've learned what my voice modulation waveform should look like when everything is working FB. If something changes, it becomes evident almost immediately.

All that said, some people do not prefer to watch a scope when they are on the air. I can understand that, although I feel like I'm flying blind without one. For those people, the mod monitor is a good tool. The audio monitor is a nice feature too.

[steve_qix]

All true to an extent. I can see EVERY peak on the scope. No need for peak hold. I can measure percentage rather closely, not that it's a big deal to me. I just want to be as close to 100% without going over on the negative peaks - all easily seen on the scope. I will not only have a quantitative measure, but a qualitative one too - I can see any hum, some distortions, oscillations, or other non-voice modulation of the carrier. In fact, over time, I've learned what my voice modulation waveform should look like when everything is working FB. If something changes, it becomes evident almost immediately.

All that said, some people do not prefer to watch a scope when they are on the air. I can understand that, although I feel like I'm flying blind without one. For those people, the mod monitor is a good tool. The audio monitor is a nice feature too.

Hi Steve,

Your eyes must be faster than mine :-).  If I watch my 'scope, there is NO WAY I can catch all of the peaks.  They go by too fast.  They're gone before I can even see most of them.  Seriously, those peaks ARE too fast (at least for me) to catch.  I find quantitative measurements on a scope to be rather cumbersome.  Have to count divisions, etc... and then the graduations are too big for anything exact... but I *do* have old eyes 

Hum... well, the 'scope will only show BAD hum.  Trying to see -30 DB or less of hum is REAL hard on a 'scope.  I have had hums I could HEAR (using my modulation monitor  , but could not SEE no matter what I did.  It was just too small.  A meter is really the only way - and you need a pretty sensitive one with expanded scale and/or gain to really catch it.  For hum, I use an old Balentine *tube* VU meter, accurate to -60 DB.  It has an audio output too!

'course, my 'scope uses about 150 watts of power and the mod monitor uses about 6 :-)  Goes along with the efficiency thing    There is probably a 12 step program somewhere for this efficiency addiction

Talk later and Regards!

Steve

[Steve - WB3HUZ]

12 steps, eh? I figured you would have optimized that to 4 or 5, for efficiency's sake.

I expect my consulting fee for playing foil here, allowing you to expound on all the reasons to get the mod monitor.

Good luck with your new endeavor.

[WA1GFZ]

Steve QIX,
Here is something to consider. take the audio output from the mod monitor and shoot it into a sound card and run "Spectran". FFT spectrum display. I find that is by far the best monitor. This way you see the peak on the led display then look at the spectrum to see what is making up the modulation. Update rates are fast not like a spectrum analyzer sweep. Then there is sdradio ver .99 or . That has a nice phase meter with the display. I'm amazed on how many VFOs are FMing slightly or drifting.
Rocky and KGKSDR are also good software packages. They also do nice AM demodulation off a low frequency IF.
I was watching Steve HUZ on heavy metal and could tell his modulation was head and shoulders above everyone coming out of his FT102.
It is all in what you want to watch. Good Luck!
I only use a scope to set the negative peak limiter.

[Blaine N1GTU]

get a load of this....

im going to run a scope AND the modulation monitor.

YEAYYY  TEST TEST YEEEAAAAYYYY 1....2

[kc2ifr]

Like I said Steve.....nice stuff....Ill leave off the tag line....was trying to funny but looks like I someone out there doesnt have much of a sense of humor. Next time please have the guts to let me know when u pull one of my posts. Again I was just making a little joke.....

[W2INR]

Bill,

According to the logs I have in front of me there have not been any posts pulled in over a month for any reason.(users pulled or moderator pulled) Are you sure you submitted the post when you were finished? Did you hit the back button after you were done? Did you put the toilet seat cover down when you were finished?

Also I ask if you have any issues with moderation on this BBS please direct your inquiries to Jay N3WWL. Jay handles the moderation of the BBS.

In regards to notification of a pulled post that is up to the moderator that pulls the post. As per the rules and regs we do not need "guts" because we do not notify of the actions taken and shouldn't have too.

[k4kyv]

More than once I have forgot to hit the "post" button after looking at the "preview."  It's extremely easy to do.  Sometimes I can hit the "back" button on the browser and bring the unposted message back up, but if the cache has expired, the message is lost for ever.  Make it a habit to check the forum index immediately to verify that your message made it.

[KA1ZGC]

Good stuff, Steve! Congrats on the product rollout, I know you've been putting a considerable effort towards this for quite some time.

WRT the scope vs. monitor debate: like everybody so far has said, it all depends on your goals, which is probably heavily biased by what you're accustomed (sp?) to.

In broadcash radio, I got used to flying with Belar monitors (not nearly as affordable) for both AM and FM. It wasn't until I started with ham AM that I started flying by scope. The scope has since become my preferred method of monitoring AM, but not to the exclusion of the ability to fly by monitor. In fact, if I had both, I would probably use both.

Which leads me to a question: is your monitor designed in such a way that a scope output could be incorporated, possibly switched from the input switch on the monitor? That would be extremely handy for those first few hours of operating a newly-built transmitter or modulator, particularly if you wanted to A/B the readings and the waveform against another unit. Even if you don't leave the scope attached, it would be nice to be able to attach one to a sampling selector such as you have built into your monitor.

Good luck with the real fun part of any new product, marketing & sales! 

--Thom
Killer Agony One Zipper Got Caught

[Glenn NY4NC]

Yep... most of us have scopes already, so a mod monitor in addition to a scope would be great.

.....but... if you don't already have a scope, the $300 you might spend on that mod monitor will buy you a very nice used Tektronix scope that would be very useful for many other tasks in addition to mod monitoring.

Get a scope first...... That being said, It would be very cool to have that mod monitor mounted directly above my rack mounted scope in the shack!.  as Blaine mentioned, ...."both"

 

get a load of this....

im going to run a scope AND the modulation monitor.

YEAYYY  TEST TEST YEEEAAAAYYYY 1....2

[steve_qix]

Good stuff, Steve! Congrats on the product rollout, I know you've been putting a considerable effort towards this for quite some time.

(snip) is your monitor designed in such a way that a scope output could be incorporated, possibly switched from the input switch on the monitor? That would be extremely handy for those first few hours of operating a newly-built transmitter or modulator, particularly if you wanted to A/B the readings and the waveform against another unit. Even if you don't leave the scope attached, it would be nice to be able to attach one to a sampling selector such as you have built into your monitor.

Good luck with the real fun part of any new product, marketing & sales! 

--Thom
Killer Agony One Zipper Got Caught

Hi Thom,

If you connected a scope, you would get audio only.  One of the major design goals was to keep the RF *away* from the monitor, which is usually mounted in a rack with other audio equipment - the last place I want to see RF   So, the pickup/detector units put out modulated DC and not RF.

Talk later and Regards,

Steve

[kc2ifr]

OOPS......looks like my post that I THOUGHT was deleted never was posted.....operator error.
What I had said in my post was as follows...." Nice stuff Steve but where is the SSB position?"
Sorry guys.....

[Mike/W8BAC]

Steve Said,

"One of the major design goals was to keep the RF *away* from the monitor"

The Collins design people saw it the same way. A separate level tunable DC circuit was installed on the RF tuning deck for this purpose on the 20V series transmitters. I suspect most broadcast transmitters of the day and since are made with similar circuits.

Mike

[Glenn NY4NC]

Nice work Steve,

Is that a plastic overlay type front panel? It would be nice to see an actual photo vs the drawing.

I will no doubt buy one once the shack is up and running down here (and I have a job  )

[steve_qix]

Nice work Steve,

Is that a plastic overlay type front panel? It would be nice to see an actual photo vs the drawing.

I will no doubt buy one once the shack is up and running down here (and I have a job  )

That's the overlay...  I'll be putting up actual pictures real soon!  Probably of the inside, too.  There are a LOT of components on that PC board!

Regards,

Steve

[K6JEK]

I'm in.  I recently scored a big beautiful Belar AMM-3A but I really want to try one of these.  I sent a note to orders at the website.

I have a scope in line but I find the peak flashers on the Belar are what I check the most.

Jon

PS:  I was surprised and pleased to hear Steve QIX check in to the 75 meter Collins AM Net, West Coast Division (!) last night.  Steve had a big, strong, beautiful signal out here in the SF area.

[W1UJR]

Looks great, but when does the Nixie tube option with the Magic eye tube come out?
I'd be all over that!

[W2VW]

OOPS......looks like my post that I THOUGHT was deleted never was posted.....operator error.
What I had said in my post was as follows...." Nice stuff Steve but where is the SSB position?"
Sorry guys.....

That is really not a joke. If you can make the monitor do anything useful on ssb the sales will go through the roof. Look at all the IHY boxes and Heil mics. MFJ just came out with a compressor/EQ unit.......