commercial broadcaster grade audio?

[unit248]

Just a heads up, I posted an article in the "amateur radio modifications" section on how to modify the Kenwood TS-850S for HiFi AM audio. I used a signal generator program on my computer to test the response, and it's nearly flat from 20Hz to 10000Hz. And that's without the DSP-100 unit. (Note: you need the DSP-100 unit for wide sideband modes.)

A local here made a short recording of me after I modified the rig, which you can listen to here:

Videogate: Bill 248 (Local Audio Check) - YouTube

(At some point I'll try to make a better recording using my other radio and post it to the modification thread.)

The hardware mods to the radio are fairly simple and cheap. The one thing that's a bit expensive is the Radial Engineering J-ISO transformer that I use to couple the balanced output from my audio gear to the unbalanced line level input on the ACC2 port on the back of the rig. There may be a cheaper alternative, but the J-ISO seems to yield the best results.

-Bill

 

[dave457]

Hey Robb

Is there realy a sound differance when useing the Mogami cable?
Was thinking of upgrading my setup with Canare StarQuad.
Your thoughts?

 

[Robb]

Hey Robb

Is there realy a sound differance when useing the Mogami cable?
Was thinking of upgrading my setup with Canare StarQuad.
Your thoughts?

Since we are using lengths less than ~10 ft; there shouldn't be a difference.
The real advantage to using the better cable is that it has far better shielding.
I use Mogami for that reason, and the fact that I have some already.

 

[Shadetree Mechanic]

Good read bump.

 

[Van Lifeson]

I know you don't buy into the tube thing.
But as a guitarist/musician for many, many years before I got into recording and live sound, tubes are easily detectable to my ear. No self-respecting blues guitarist that I have ever played and recorded with - including bassists - would ever use a solid state rig. In recording, the tube preamps have a definable 'phat' sound that only the real high-end/ultra expensive solid state preamps could attempt to emulate. Tubes have always sounded better - and they always will - IMO . . .

BB King played a solid state amp.

 

[Robb]

BB King played a solid state amp.

Yes, a Lab L5 IIRC. Ever used one? They have a parametric eq tone section and built-in compressor too. But he didn't start out or get famous on an amp that came out in the late seventies; he got famous with a Fender tube amp with that creamy, fat tone. The Lab L5 just kicked in some punch and compression circuit to emulate, since most tube amps naturally compress a bit because of the tube rectifier.

 

[Van Lifeson]

He must have liked the SS amp better to make the switch then.Who knows.
And who really cares anyway. i do think he would have become famous using SS from the start though. Tubes didn't make him great.

 

[Robb]

He must have liked the SS amp better to make the switch then.Who knows.
And who really cares anyway. i do think he would have become famous using SS from the start though. Tubes didn't make him great.

It did lend to the blues style of playing. But jazzists use tube for the same reason. Sure helped a lot. My first tube guitar amp was made in Japan by a company names 'Elk' Had four 6BQ5's. But as soon as I could get some more money together, got a Fender Bandmaster then a Fender Bassman amp. Pure 6L6-GC silk with a tube rectifier.

 

[Shadetree Mechanic]

Still a good read. Bump.

 

[dave457]

Wonder what ever happened to Bill unit 248...
He had a wealth of great info

 

[Shadetree Mechanic]

Bump. Get your station ready for when the skip starts rolling.

 

[Shockwave]

Hi-Fi is pleasant to listen to when the signal is strong and not suffering from any selective fade. The wider the signal is, the harder it is to keep the sidebands in phase with the carrier. Ever notice how much less selective fade you hear on DX signals when on SSB versus AM? That's a direct result of the signal being half the bandwidth. On AM the problem is even worse because when the carrier is out of phase with the sidebands, the opposing sidebands can cancel each other out.

The military learned this in the 1940's (or earlier) and is why we have the term "military grade audio". It cuts through with intelligible voice because it's narrow. When you double the bandwidth of your transmitted signal, it also takes twice as much power output, to produce the same signal strength. Radios that I use for DX have been modified so that I can switch between broadcast fidelity when conditions are quiet, and communications or military grade audio when I'm more concerned about getting heard, than how much bass and treble I can get in your receiver.

Today, I don't even use a bit of external gear. The average radio has all of the key parts to produce Hi-Fi. You just have to know how to reconfigure the audio output chip to support it and modify coupling and bypass caps in the mic pre amp stages to supply it. Plug a good mic right in the front panel and easily obtain 20hz to 10khz of relatively flat response. No EQ required. Just bass and treble adjustments with one adjustable notch filter, that is set to get the mud out around 200 cycles.

 

[sunbulls]

Hi-Fi is pleasant to listen to when the signal is strong and not suffering from any selective fade. The wider the signal is, the harder it is to keep the sidebands in phase with the carrier. Ever notice how much less selective fade you hear on DX signals when on SSB versus AM? That's a direct result of the signal being half the bandwidth. On AM the problem is even worse because when the carrier is out of phase with the sidebands, the opposing sidebands can cancel each other out.

The military learned this in the 1940's (or earlier) and is why we have the term "military grade audio". It cuts through with intelligible voice because it's narrow. When you double the bandwidth of your transmitted signal, it also takes twice as much power output, to produce the same signal strength. Radios that I use for DX have been modified so that I can switch between broadcast fidelity when conditions are quiet, and communications or military's grade audio when I'm more concerned about getting heard, than how much bass and treble I can get in your receiver.

Today, I don't even use a bit of external gear. The average radio has all of the key parts to produce Hi-Fi. You just have to know how to reconfigure the audio output chip to support it and modify coupling and bypass caps in the mic pre amp stages to supply it. Plug a good mic right in the front panel and easily obtain 20hz to 10khz of relatively flat response. No EQ required. Just bass and treble adjustments with one adjustable notch filter, that is set to get the mud out around 200 cycles.

The example I sometime use is the female voice that lacks much of the bass is easier to understand, especially under adverse conditions.

 

[Shockwave]

The example I sometime use is the female voice that lacks much of the bass is easier to understand, especially under adverse conditions.

The "numbers stations" we sometimes heard on shortwave, used a female voice to broadcast that endless list of numbers, for a reason.

 

[Onelasttime]

I know I will regret sharing this since it will be abused. No this is not studio sound! LOL

Kids in my area love this though so I had to post it!