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Composite Clipper

D

dannyscott101

I have installed a CP-803 in our airchain in an attempt to squeeze a bit more competitive modulation without spending a lot of $$$. (or any $ for that matter!)

If you read my old posts about the Orban Optimod-TV (8282) and Optimod-2200 combo that is on the air, you can get up to date on that...

The trouble is that it is now installed, I'm driving it a considerable amount into the 'safe' zone, but it has resulted in very little (if any) perceived difference in loudness. We are still by far the "quietest" sounding commercial station on the dial. We have made comparisons on a modulation monitor, and stations in the market that have legal modulation readings are kicking our ass in loudness! One of these stations I know to be still running an 8200 on air.

When I started out, I had left the 2200's clipper settings in the 'original' positions, and found that driving significantly into the CP-803 resulted in unacceptable distortion levels on air, and only a moderate increase in perceived loudness. I ended up backing off the 2200 settings to attempt to drive the CP-803 a little harder. The current clipper settings are CLIPPING -4.0 (the minimum setting) and FINAL CLIP +.08.

The on air sound is now pretty clean, but not much (if any) louder sounding.

I have been running the 8282s EQs pretty close to flat, and using the EQ adjustments in the 2200 to get the desired sound. Could the use of the EQ controls on the 2200 be reducing the CP-803s ability to process effectively?

I do understand that I'm not going to compete with a very modern processor with my chain of ancient artifacts, but I did expect the CP-803 to make SOME noticeable difference.

I know I have not given all the information on every setting here, but I would appreciate any constructive comments.
 
I have recently bought a cp-803 clipper,and after modding it,i was going to play with it on the o/p of my 8200 just to see if any loudness could be had.
I also have an 8282 as well.

What i would do is back off the final clipper in either the 8282 or 2200,and would try a setting of say -2db and make up at least this difference with the cp-803.
I would probably use the multiband clipper at approx 0db.

The reason for this is i expect the final clipper to cause much of the distortion,as this is what i have been lead to believe is where the greatest improvements have been made in later processors.

Also i did look at the possibility of modifying the 8200/8200 to install a hard clipper on the l and r audio to the encoder,and then feeding the clipper from the variable audio out instead of the fixed feed as it is now.
 
Here's a thought from left field:

FM running satellite music (AC) through Omnia 3T and Armstrong exciter, thence into Harris 10K.
We bought second station, Energy-Onix transmitter and exciter, exciter dying. Bought used Continental 802B & refurbished it with the intent to replace the Energy-Onix exciter. Slight problem: It's a leased site with a community rack, and the rack has outlet boxes and cables that prevent mounting the deeper Continental; the Armstrong exciter is the exact same depth as the Energy-Onix.

So we install the 802B at the first station then moved the Armstrong into the second station. Didn't change the processing on the Omnia 3T, just set the modulation level on the 802B. Next day:

"Hey, what did you do to make the station sound louder???"
 
Actually i have not yet modded it,but will be doing so very soon,this is my second cp-803.
The mods are replacing the opamps and sorting out the supply ground,as well as replacing the tants that are in the mpx path.

This was recently outlined here on Radio-Info by another member.

Approx 8+ years ago i modded my first cp-803 but sold it several years later.
I have been looking for the detailed mods i did then,but as yet cannot find them.

As time goes by the info for mods gets scattered,paper and data files get misplaced,i will have to collect them all and back them up on hard drive and memory stick.
 
Some of the older Armstrong exciters have composite clippers built in. I never remember it being on the feature list or much about it in the documentation, but it works extremely well. Best and cleanest composite clipper Ive used. Most of the exciters with the blue backlit LCD screen have them.
 
By far and away, the best composite clipper I've ever heard was made by Steve Hemphill. Thing weighed about 30-40 pounds, as I recall...as the transformers were hand-wound. It sounded like a million dollars.

The only thing I would use an 803 for is to place at the far end of an STL hop to help with overshoots.

I'm sure someone's told you this already, or you've read it here...

If you're enjoying daisy chaining a bunch of equipment together, and experimenting, that's one thing. By all means, have fun, I get it, trust me.

If you really want to have a dial dominant sound (or just gorgeous) for not a lot of money?

Your best bet is to buy, build, or configure a machine that meets the specifications on ceaudio.com and get Breakaway Broadcast (ASIO). Their future versions will include RDS...and the future version will have more flexibility (EQ, etc)

It is, by far, among the finest broadcast audio processors out there RIGHT NOW. I don't care if it runs on a modern computer, handheld calculator, or abacus. It sounds incredible.

It's a player. Seriously.
 
Sgeirk said:
If you really want to have a dial dominant sound (or just gorgeous) for not a lot of money?

Your best bet is to buy, build, or configure a machine that meets the specifications on ceaudio.com and get Breakaway Broadcast (ASIO). Their future versions will include RDS...and the future version will have more flexibility (EQ, etc)

It is, by far, among the finest broadcast audio processors out there RIGHT NOW. I don't care if it runs on a modern computer, handheld calculator, or abacus. It sounds incredible.

It's a player. Seriously.
Click to expand...

I can't argue with this... but I still hear, "I don't want to depend on a computer running up there."
 
Run the clipping where you normally would on the processors, and then use the CP-803 to catch the overshoots. If you turn down the clipping on your main box, then turn up the CP-803, you're back to where you started from.

Make the most use of the distortion-canceled multi-band clippers on the 8282, run the main clipping at 0 on it. Run the final clip no higher than +.5 on the 2200. Then set the CP-803 for the yellow light to blink on and off, while it's still relatively clean. Don't let the red light go on. You can back off to a point on the main clippers, but only so far.

I also agree with the Breakaway comments. Get a rack mount PC with a solid state hard drive, and run the mare minimum of Windows XP, and a DC coupled sound card. OR put the PC at the studio, and then send stereo audio to the 2200 and use it as a stereo generator only. That will work well too.

I've got an Omnia 11 arriving for a client this week, at the other end of the spectrum of processing ;D
 
Following up on TomT, my first question would be, "what's the transmitter?" Over the years I have run in to several transmitters, particularly 10kw from the big H, that were narrow band and suffered from lack of loudness and low end. At one time, I replaced a then 10 year old 20H3 with a brand new 20H3, and the difference in sound was phenomenal. We swapped exciter outputs between the transmitters, and the better sound stayed with the new transmitter (old exciter, etc.). The test there, and may useful here to eliminate the transmitter as the potential problem, would be to compare exciter only (PA off) to other signals that you normally find louder. Looking at AM noise with modulation vs. no modulation is often meaningful too (it shouldn't be much higher).
 
Adding to the previous post, if it's a tube job you want to tune for minimum incidental AM noise, which isn't always at the point of greatest efficiency. That will also center your passband and improve the audio.

And yes, what exciter are you using? Besides the main TX, I've replaced exciters before and have had a noticeable difference in loudness and clarity.
 
To answer the prior questions, it's a Harris HT-3.5 with THE-1 exciter, circa 1989.

The backup is an Armstrong exciter and amp, but I forgot to check the model #.

It always seems like we sound a little better when the Armstrong is on the air, but's it's been a while since I've made the direct comparison.

After I read this today I just squeezed a smidge more out of it by taking down the final clip on the 2200 while increasing the main clipping to -2.0, AND increasing the multiband clip on the 8282 to '0' from its prior setting of -5 (or whatever the minimum is)

I was surprised that it would help increasing clipping in the 'earlier' stages.

I was monitoring with cans on my old Vector Research VR-5000 while I did the tweaking.

I wouldn't say it's the best sound in the world, but pretty darned competitive considering that not a single piece of gear in the chain is less that 15 years old!
 
I like the idea of running Breakaway at the studio, but right now we are running T1 lines (that have had reliability issues in the past.) A Barix is on backup duty with the switch point prior to the processing.

I have no expertise on T1 lines, (or a lot of things for that matter) but I assume there is no way to run a composite signal intact through them.

Our previous studio location had an STL to our old tower site. The 'new' tower site that we moved to back around 2001 had no direct shot, thus the T1s.

As of a year ago, the 'new' studio once again gives us a shot at the 'new' tower, so an STL may return.
 
dannyscott101 said:
I like the idea of running Breakaway at the studio, but right now we are running T1 lines (that have had reliability issues in the past.) A Barix is on backup duty with the switch point prior to the processing.

I have no expertise on T1 lines, (or a lot of things for that matter) but I assume there is no way to run a composite signal intact through them.

Our previous studio location had an STL to our old tower site. The 'new' tower site that we moved to back around 2001 had no direct shot, thus the T1s.

As of a year ago, the 'new' studio once again gives us a shot at the 'new' tower, so an STL may return.
Click to expand...

You could run the composite Breakaway signal thru the T1 - just make sure that it isn't going thru any bit reduction (compression). If you have a Harris Intraplex T1 unit, you should just be able to get different timeslot cards to sent a uncompressed composite signal from studio to tx.

Ask your engineer if it can be done.
 
Run stereo though the T1 from Breakaway, straight into the stereo generator portion of the 2200. I think you can do that, but it's been awhile since I've messed with one of those. Or just put the pre-emphasized audio into the test jacks on an 8100 to use it as a stereo gen only. That works, I've tried it with very good results. No need at this point to try and shove a composite signal down the T1.
 
WNTIRadio said:
Run stereo though the T1 from Breakaway, straight into the stereo generator portion of the 2200. I think you can do that, but it's been awhile since I've messed with one of those. Or just put the pre-emphasized audio into the test jacks on an 8100 to use it as a stereo gen only. That works, I've tried it with very good results. No need at this point to try and shove a composite signal down the T1.
Click to expand...

I like this idea, HOWEVER...

In both cases of running either the composite or preemphasized audio down the T1s, would there not be significant overshoots on the other end of the T1, even running uncompressed?...

In addition, this would complicate the issue of the Barix for backup. This would then require a separate chain for just the Barix (to a separate processor) at the transmitter. In addition, this would require a trip to the stick in the event of T1 failure... Right now, the switchover from T1 to Barix can be done remotely and quickly. There is an extra 8100 up there, but I would hate to put it to use for such an infrequent task.
 
You can send the preemphasized audio down the T1, as long as it's uncompressed. It's already filtered to 15khz and clipped to perfection, an uncompressed STL running 44.1khz (or 48khz) should pass it without any problem. Run that into the 8100's test jacks, set up the levels for 100% modulation and off you go. I've done it, and it works quite well. Use the 2200 for the Barix connection as the backup. All the 8100 is doing is being a stereo generator, taking the processed feed from the STL and making it stereo.
 
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