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Author Topic: Inovonics 223  (Read 4132 times)
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KD1SH
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« on: December 14, 2022, 01:07:32 PM »

  Came across a used Inovonics 223 last week, in mint condition and for a great price, so I couldn't resist. I've always wanted to try one, but the price of new ones always kept me away, and most people selling them pretty much ask nearly new prices.
  Okay, I'll admit right up front that part of the attraction was the sheer audacity of using a high-tech device like the 223 on an old DX-60!  But, my DX-60 has the WA1QIX mod - pristine sine sweep from 50hz all the way to 18khz - so it's not a complete misappropriation of digital technology.
  Just figured I'd share a few observations: To begin with, it does everything that Inovonics promises, pretty much seamlessly. The bandwidth control is amazingly tight; if you set it for 5kz wide (which will give you 10khz transmitted bandwidth), that's exactly what you get; on a waterfall display it looks just like the transmission from an SDR, a solid swath painted down the screen with a brick-wall on either side, and you can really "fill up" that bandwidth. Same for the modulation percentage, if you set it for +120%, the 223 puts up a wall right there; nothing beyond that will get through. It's adjustable from +99% to +140%. The "gain-riding" AGC works fine, but personally I couldn't see any huge benefit for ham radio use.
  The compression and limiter settings take some work to dial in - listening to yourself through headphones and recording your transmissions on an available WebSDR is a big help. Likewise for the crossover and EQ settings. It's a line-level input device, so of course you'll need some upstream microphone amplification. The input and output levels have a wide range of adjustment.
  The only real issue I had isn't a problem with the Inovonics 223 itself, but rather with my DX-60. The transmitter responds quite asymmetrically to audio input, taking more audio amplitude to generate negative modulation than positive, so that when I set up the Inovonics to generate 100% positive modulation I only get around 80% negative. No big deal, but it means that I can't limit my modulation to +100% without sacrificing the negative peaks. But, that's just the nature of an old boat-anchor dragged kicking and screaming into the modern world.
  Some downsides: Since the 223 was designed for broadcast rather than ham radio, there's some lack of flexibility inherent in it, mainly the fact that you can't change bandwidth settings on the fly. The bandwidth settings are each associated with a particular "program", and when you change from one program to another, all of your other settings - input and output gain, compression and limiter settings, and EQ - get wiped out, so you've got to start all over again. It would be nice if it also had a 3khz bandwidth setting in addition to the 5, 7, 9 and 10 khz settings, but again, it's a broadcast device by design intent.
  All in all, it's a nifty little box, though probably more applicable to a K7DYY rig than a DX-60, and though I would probably never have laid out $1000 for a brand new one, I'm glad to have found this one for a good price. It's a keeper.
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« Reply #1 on: December 15, 2022, 02:56:29 PM »

Connect the output of the I 223 to the cathode of the DX-60 second stage speech amp and crank the I 223 output level down.

Phil AC0OB
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KD1SH
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« Reply #2 on: December 15, 2022, 06:49:46 PM »

Phase inversion without the need to mess with any of the external gear - intriguing idea.

Connect the output of the I 223 to the cathode of the DX-60 second stage speech amp and crank the I 223 output level down.

Phil AC0OB
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« Reply #3 on: December 16, 2022, 09:36:44 PM »

  Came across a used Inovonics 223 last week, in mint condition and for a great price, so I couldn't resist. I've always wanted to try one, but the price of new ones always kept me away, and most people selling them pretty much ask nearly new prices.
  Okay, I'll admit right up front that part of the attraction was the sheer audacity of using a high-tech device like the 223 on an old DX-60! 
...

Sheer audacity is its own reward!
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KQ6F
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« Reply #4 on: March 31, 2023, 03:51:26 PM »

Hi KD1SH -

Am considering getting the 223 as an upgrade to my Symetrix 528e/Inovonics 222 combo. The thing that bothers me about my present setup is that I can't get the audio highs I want.  I crank up the highs on the Symetrix as far they'll go but the peak limiter in the 222 knocks them down again.  Since the peak limiter in the 223 follows its EQ block, I'm guessing the same will happen in the 223.  Or perhaps the knockdown is not so severe?  Would appreciate any feedback on this.

73, Rod KQ6F
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KD1SH
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« Reply #5 on: April 01, 2023, 02:14:07 PM »

Well, I've got no experience with the 528E or the 222, so I can't say much about those. I do know that with my 223, whatever I set the bandwidth to - in my case 5KC, or or 10KC total - it will fill that bandwidth right up, and on a waterfall display it looks just like the signal from an SDR: razor sharp shoulders. And, if I set it to 10KC wide - 20KC total - it fills that right up, too. I don't run it that way on the air; that's a hell of a lot of bandwidth to occupy. My modified DX-60B will take whatever I feed into it, all the way to 20KC.
How high are you trying to go?


Hi KD1SH -

Am considering getting the 223 as an upgrade to my Symetrix 528e/Inovonics 222 combo. The thing that bothers me about my present setup is that I can't get the audio highs I want.  I crank up the highs on the Symetrix as far they'll go but the peak limiter in the 222 knocks them down again.  Since the peak limiter in the 223 follows its EQ block, I'm guessing the same will happen in the 223.  Or perhaps the knockdown is not so severe?  Would appreciate any feedback on this.

73, Rod KQ6F
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KQ6F
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« Reply #6 on: April 01, 2023, 09:43:28 PM »

I've modified the LPF on my 222 to 5.7kHz.  And have pumped up the high end EQ on the 528e to max at 4.7Khz. So like I said, the peak limiter in the 222 just bumps its back down.  The guys I talk to say I sound fine but lack sibilance. 

Am wondering if you have boosted your EQ on the 223?  Also wondering how you've set your Limiter Drive?

KQ6F
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KD1SH
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« Reply #7 on: April 02, 2023, 09:05:20 AM »

You know, I've never actually engaged in a "settings net" to fine tune my settings on the air. I took my best guess at most of them, for a start, and recorded myself on some WEBSDR's. The consensus of people I talk with is that it sounds great the way I've got it set, so I've pretty much settled in with the settings as they are. Maybe it could be better, but on-air fine tuning gets tedious.
I've got my limiter drive set to +22.
Bass EQ = -2
High EQ = +5


I've modified the LPF on my 222 to 5.7kHz.  And have pumped up the high end EQ on the 528e to max at 4.7Khz. So like I said, the peak limiter in the 222 just bumps its back down.  The guys I talk to say I sound fine but lack sibilance. 

Am wondering if you have boosted your EQ on the 223?  Also wondering how you've set your Limiter Drive?

KQ6F
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« Reply #8 on: April 02, 2023, 05:02:58 PM »

I've modified the LPF on my 222 to 5.7kHz.  And have pumped up the high end EQ on the 528e to max at 4.7Khz. So like I said, the peak limiter in the 222 just bumps its back down.
KQ6F
According to the 222 manual, it’s more an NRSC compliance device than a processor. Besides the brick wall LPF and attendant limiting/overshoot compensation, it pre-emphasizes the high end, then limits it. If you’re boosting highs and it is too, then limiting them, your external boost may well disappear.  You might try turning off the 222’s pre-emphasis, and see if that helps. 

Ed
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AJ1G
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« Reply #9 on: April 04, 2023, 02:07:18 PM »

Ah Ha! Now I know why your audio looked so tight in bandwidth cutoff on the spectral and waterfall display of my in-shack SDR during the AM Carrier Net on Sunday!    I was thinking, how is he getting that tight a mask on the bandwidth with the DX-60 , even with the QIX audio mods?  Looked like an SDR generated signal, and sounded great.

Yes the best way to figure out how your signal sounds is to listen for yourself on a Web SDR and make air check recordings from them.  I am amazed at the number of operators who are still constantly asking for others to tell them how they sound, many of them have been repeatedly told about using the Web SDRs, using a local off the air monitor receiver or a simple "sniffer" detector feeding an audio amplifier, and an O scope for envelope monitoring. 
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Chris, AJ1G
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KQ6F
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« Reply #10 on: April 04, 2023, 07:30:18 PM »

Am still debating whether to buy one of these.  I wish I could find a used one at a discounted price.

I would love it if somebody would send me a .wav file of how it sounds.  Maybe one recorded of KD1SH off a WebSDR?  That might get me off my butt.

My email address is good on QRZ.

Rod KQ6F
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KD1SH
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« Reply #11 on: April 05, 2023, 12:50:37 PM »

Thanks, Chris, for the complement on the audio. As always, on the air or elsewhere, I'll give the credit to Steve's superb mod for the DX-60; I just did the soldering.
The whole audio chain is a Bluebird-SL large diameter condenser mic; DBX286-S mic-amp, and the Inovonics 223, with line-level direct to the dx-60.
I also run Steve's REA Mod Monitor.
I've always felt that getting into a QSO with multiple operators and then asking "how's my audio?" followed by, "wait a minute while I make some adjustments," and then, "how's my audio now?" and repeating the process over and over again ad-nauseam is imposing yourself on everyone else, unless of course that's the agreed point of the QSO. And, so many times, you'll hear an operator putting everyone through that very same routine, and then a few evenings later he's back, telling everyone, "okay, I've made a few changes to my settings - how's my audio now?" And the whole tedious process begins anew.

Ah Ha! Now I know why your audio looked so tight in bandwidth cutoff on the spectral and waterfall display of my in-shack SDR during the AM Carrier Net on Sunday!    I was thinking, how is he getting that tight a mask on the bandwidth with the DX-60 , even with the QIX audio mods?  Looked like an SDR generated signal, and sounded great.

Yes the best way to figure out how your signal sounds is to listen for yourself on a Web SDR and make air check recordings from them.  I am amazed at the number of operators who are still constantly asking for others to tell them how they sound, many of them have been repeatedly told about using the Web SDRs, using a local off the air monitor receiver or a simple "sniffer" detector feeding an audio amplifier, and an O scope for envelope monitoring. 
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KD1SH
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« Reply #12 on: April 05, 2023, 01:06:29 PM »

I was very happy to find a used one for less than half the new price.
Just a thought: I've heard very good things about the Schlockwood SW200, and its brand-new price is less than half the new price of the 223.
There's also the MAX Audio Processor, and though I've got one, I must admit - somewhat embarrassingly - that though I've finished assembling the board, and obtained a nice case to install it in, I got distracted and haven't finished the project yet. I've heard one on the air - Clark, N1BCG, runs one - and it sounds superb.
Unfortunately I didn't save any of my WebSDR recordings, but I'm thinking that I'll do another recording Sunday morning, during the AM Carrier Net, and I can send you one.

Am still debating whether to buy one of these.  I wish I could find a used one at a discounted price.

I would love it if somebody would send me a .wav file of how it sounds.  Maybe one recorded of KD1SH off a WebSDR?  That might get me off my butt.

My email address is good on QRZ.

Rod KQ6F
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"Gosh, Batman, I never knew there were no punctuation marks in alphabet soup!"
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KQ6F
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« Reply #13 on: April 05, 2023, 01:44:36 PM »

I had the SW200 for awhile.  It was OK but I found it to be better suited to LPAM hobby broadcasting than ham radio.  I didn't need its gated AGC nor its pre-emphasis and had them both shut off.  Also I found its LPF not sharp enough to suit me.  And finally it didn't have look-ahead limiting.

Will look forward to hearing your .wav recording.

73, Rod
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N1BCG
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« Reply #14 on: April 05, 2023, 02:51:13 PM »

There's also the MAX Audio Processor, and though I've got one, I must admit - somewhat embarrassingly - that though I've finished assembling the board, and obtained a nice case to install it in, I got distracted and haven't finished the project yet. I've heard one on the air - Clark, N1BCG, runs one - and it sounds superb.

A world of thanks for the nice words! I'm using the MAX 495 with modifications that are incorporated in the 500 model which is about to become available. If you're interested in the latest MAX then you can trade in what you have. The improvements have been significant.

More information is available here: https://www.internetwork.com/MAX

Only the landing page has been updated so far...

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WD8BIL
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« Reply #15 on: April 06, 2023, 10:22:47 AM »

I couldn't get the highs I wanted out of my Viking 1 a few years back. Tried everything with the processing. (CRL equipment)

Then Robert W0VMC mentioned the plate bypassing in the Viking. I changed the bypass cap at the bottom of the plate choke and BOOM. There they were!

Just something to think about.
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KQ6F
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« Reply #16 on: April 08, 2023, 02:14:37 PM »

Ignore.  Tried to Delete this post but can't find the Delete button

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