Is it possible to direct inject tx audio on the ts430s on AM? I mainly use this rig on ssb but tinkering around the idea of using it on AM and would love to do a hifi setup. What needs to be done? Worth it?
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HIFI audio on AM, ts-430s?
- Thread starter Crasher
- Start date
RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
You could get an Inrad filter that is wider than the stock unit, they do make them.
But as well as that, any radio can benefit from using a mic that has a flatter, cleaner freq response.
That's just physics.
Even Ham radios, especially if they are older, sometimes need to be re-aligned and checked out.
As far as reaching directly into the balanced modulator, I'm sure it could be done, but I have never done that to this radio.
Clean, clear, and wider audio always wins - IMO.
Over-modulated, over-driven audio is never the right thing.
But as well as that, any radio can benefit from using a mic that has a flatter, cleaner freq response.
That's just physics.
Even Ham radios, especially if they are older, sometimes need to be re-aligned and checked out.
As far as reaching directly into the balanced modulator, I'm sure it could be done, but I have never done that to this radio.
Clean, clear, and wider audio always wins - IMO.
Over-modulated, over-driven audio is never the right thing.
MC-60 is on the way actually. What Inrad filter should I be looking for exactly? I do have the yk-88a filter installed, but only rx goes through that filter I thought? TX still uses the narrow filter, unless there is a mod to tx through the wider filter?
Thanks for the info!
Thanks for the info!
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I would investigate some of the HiFi AM mods for the TS-440. The 440 and 430 both use the same AM transmission scheme (unbalancing the AN612 balanced modulator). As has been noted, the key issue is filtering: direct injecting the balanced modulator will help you avoid any limitations in the mic preamp circuits, but the filters in the radio will still limit your TX bandwidth. You can either replace the existing AM filter with a much wider one, or bypass it entirely (in which case you'll go really wide).
A lot of people prefer the TS-850S for this because it offers a user-configurable filter selection scheme which, with a hidden service menu trick, can be tweaked to allow filter selection in TX as well as RX. This means you can bypass the filtering without any hardware mods.
I would get a copy of the TS-430 service manual and look around a bit to see what you're in for. In theory it shouldn't be too hard to add relays or something to bypass the filter during TX.
-Bill
A lot of people prefer the TS-850S for this because it offers a user-configurable filter selection scheme which, with a hidden service menu trick, can be tweaked to allow filter selection in TX as well as RX. This means you can bypass the filtering without any hardware mods.
I would get a copy of the TS-430 service manual and look around a bit to see what you're in for. In theory it shouldn't be too hard to add relays or something to bypass the filter during TX.
-Bill
RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
You might also want to check out the link below. I'm not trying to steer you away from experimenting because I had sweet rack of audio gear feeding an Icom 756Pro II a few years back and had fun with it. But the Icom had an adjustable tx bandwidth of up to 3 khz and I could push it a little further with an eq. I never got any bad reports but the potential for splatter was still there. At the end of the day I had audio reports that were just as good with my Heil GM-4. You can buy and play with audio gear all day long but the fact remains that out ham radios are designed for communications audio; not meant to be a commercial broadcast station.
ESSB HiFi SSB transmitter bandwidth splatter
ESSB HiFi SSB transmitter bandwidth splatter
RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
unit248;446631 A lot of people prefer the TS-850S for this because it offers a user-configurable filter selection scheme which said:Bill,
Is that the 850 or the 870? My 850 was happily menu free. Of course I owned it quite a while ago. I know the 870 had configurable bandwidths.
Oscilloscope Monitoring | eSSB | SSB | AM Audio Modulation, Amplifier and System Linearity
The only 'splatter' that is possible - that I am aware of - would be having the ALC too wide open on SSB mode. A radio can TX as wide as the filtering will allow, and can even be byassed altogether.
Running audio gear for best results isn't as simple as one might think. Ask someone who worked in a recording studio. Oftentimes, less is more. Guys go to school how to do that, and end up taking in years of experience before they can even be considered to be a real 'pro'. If equalization is the issue; then a mic better suited is chosen, rather than EQing both pre and post recording. Compression is real art form, and is often the one processor that is least understood and often done incorrectly.
The complaints made by some Hams is a 'sour grapes' argument concerning eSSB. They don't understand it, it is new and therefore threatening, and are unwilling to understand its place as valid experimentation. Because 'Joe Blow told me so". The proof of this is their claim that the amateur is 'attempting to have a commercial broadcast station'. That is the tip off, not because that would be impossible to do, but rather because that is not the goal. That would violate amateur rules of proper freq use.
Besides the presence of filters in a radio, the engineers have also added caps to the mic audio circuit that cause the mic freq to begin the process of shutting off before it reaches the filter for both the low and high freqs. This helps the filter have a better shut-off slope when it kicks in. The reason to inject directly into the balanced modulator is to avoid all of that. The other option would be to change the values of those caps, and that can also be done. Been there, done that.
Having run a FlexRadio SDR-1000 ('my fave'), I can tell you that the filtering in it is all done digitally. There is no such distortion because it is running 20k wide to another radio. The PA section cannot tell the difference, IIRC. The problem is found in the 'other radio' because it cannot hear all of what the other radio is putting out. No skin off of anyone's nose, except that running 20k wide will take up too much bandwidth under the rules is all.
Just because some radio operators have made mistakes trying to do eSSB, it does not preclude that it cannot be done correctly. Neither is it necessary to have a SDR-1000 to do it right. There are plenty of eSSBers that have YouTube videos that prove conclusively that it can in fact be done right. It is fun, and it makes the hobby more interesting than it was ten years ago - IMO.
The only 'splatter' that is possible - that I am aware of - would be having the ALC too wide open on SSB mode. A radio can TX as wide as the filtering will allow, and can even be byassed altogether.
Running audio gear for best results isn't as simple as one might think. Ask someone who worked in a recording studio. Oftentimes, less is more. Guys go to school how to do that, and end up taking in years of experience before they can even be considered to be a real 'pro'. If equalization is the issue; then a mic better suited is chosen, rather than EQing both pre and post recording. Compression is real art form, and is often the one processor that is least understood and often done incorrectly.
The complaints made by some Hams is a 'sour grapes' argument concerning eSSB. They don't understand it, it is new and therefore threatening, and are unwilling to understand its place as valid experimentation. Because 'Joe Blow told me so". The proof of this is their claim that the amateur is 'attempting to have a commercial broadcast station'. That is the tip off, not because that would be impossible to do, but rather because that is not the goal. That would violate amateur rules of proper freq use.
Besides the presence of filters in a radio, the engineers have also added caps to the mic audio circuit that cause the mic freq to begin the process of shutting off before it reaches the filter for both the low and high freqs. This helps the filter have a better shut-off slope when it kicks in. The reason to inject directly into the balanced modulator is to avoid all of that. The other option would be to change the values of those caps, and that can also be done. Been there, done that.
Having run a FlexRadio SDR-1000 ('my fave'), I can tell you that the filtering in it is all done digitally. There is no such distortion because it is running 20k wide to another radio. The PA section cannot tell the difference, IIRC. The problem is found in the 'other radio' because it cannot hear all of what the other radio is putting out. No skin off of anyone's nose, except that running 20k wide will take up too much bandwidth under the rules is all.
Just because some radio operators have made mistakes trying to do eSSB, it does not preclude that it cannot be done correctly. Neither is it necessary to have a SDR-1000 to do it right. There are plenty of eSSBers that have YouTube videos that prove conclusively that it can in fact be done right. It is fun, and it makes the hobby more interesting than it was ten years ago - IMO.
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Bill,
Is that the 850 or the 870? My 850 was happily menu free. Of course I owned it quite a while ago. I know the 870 had configurable bandwidths.
The TS-850 has configuration menu that lets you adjust certain functions. It isn't very sophisticated, but it's there.
For example, normally the radio emits a set of morse code beeps through the speaker when you select a mode, to announce what mode you just chose (AM, FM, USB, LSB, CW). The configuration menu can be used to turn this off, which I did because it just bugged me. You can also set the M.CH/VFO CH and main tuning knob stepping rates, select which subaudible tone to use for 10meter FM repeater operation and a few other things. The whole list is documented in the user's manual. To access the menu, you have to press and hold the LSB/USB button on the front panel while you power the rig on.
In addition to this, there is also a hidden service menu, which you can access by pressing and holding both the SCAN and TX/M.CH keys while powering the rig on. By default it shows you a checksum of the firmware for the main computer. If you select option 1 from this menu and set it to 'on' you will be able to use the 8.83 and 455 buttons to select the filter settings in transmit as well as receive. (Normally if you press these buttons with the transmitter engaged, nothing happens.)
If you do this, and you direct inject the balanced modulator, and you set the 8.83Mhz IF filter to the bypass position, _and_ if you install a jumper wire in the 455Khz CW filter slot and use this as a bypass position for the 455Khz IF, you can get almost 10Khz of AM audio bandwidth.
-Bill
Not sure if the rig has a ACC2 port, but if it does, you can feed audio directly in it
And with a few cap changes and a better 455 filter, the rig will sound a lot better, smother, cleaner with audio gear in both the RX and TX for AM. At least is does with my 440
And with a few cap changes and a better 455 filter, the rig will sound a lot better, smother, cleaner with audio gear in both the RX and TX for AM. At least is does with my 440
Unit248 is on the right track. You want to bypass the YK-88A filter in TX. You should use a double throw double pole relay to do this because you can't just jump across the filter. The filter must be completely removed from the circuit in TX. Otherwise the filter will still load the circuit and reduce bandwidth.
Don't worry about bypassing this filter. The radio will not get too wide because there are about a dozen other areas limiting the bandwidth to a reasonable level. The filter is the biggest road block. Buying an aftermarket filter will not make you sound better than bypassing the stock one.
Bypassing the filter will be the easiest big improvement you can make but the radio will still have problems producing anything over 100% positive peaks due to the balanced modulator inverting strong positive peaks. Using the speech processor is a must on AM to prevent this.
Don't worry about bypassing this filter. The radio will not get too wide because there are about a dozen other areas limiting the bandwidth to a reasonable level. The filter is the biggest road block. Buying an aftermarket filter will not make you sound better than bypassing the stock one.
Bypassing the filter will be the easiest big improvement you can make but the radio will still have problems producing anything over 100% positive peaks due to the balanced modulator inverting strong positive peaks. Using the speech processor is a must on AM to prevent this.
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