Icom 756: Increasing the TX and RX Audio Bandwidth
Icom 756: Increasing the TX and RX Audio Bandwidth
Hello everybody!
In case someone wants to increase the audio bandwidth on the Icom 756 (non-Pro), I've written a short report explaining the changes I've made to my rig.
I would post the link here, but the system does not allow me to do that yet. Will do as soon as I can post url's!
Anyway, with this mod you can get more than 5 kHz of SSB / AM TX bandwidth. The patch is pretty clean and it has been working nicely for several months now.
Daniel
In case someone wants to increase the audio bandwidth on the Icom 756 (non-Pro), I've written a short report explaining the changes I've made to my rig.
I would post the link here, but the system does not allow me to do that yet. Will do as soon as I can post url's!
Anyway, with this mod you can get more than 5 kHz of SSB / AM TX bandwidth. The patch is pretty clean and it has been working nicely for several months now.
Daniel
Now I can, so here it is!
http://wz5q.net/docs/ea3hru_ic756_rx_an ... h_mods.pdf
Comments and suggestions are welcome !!!
http://wz5q.net/docs/ea3hru_ic756_rx_an ... h_mods.pdf
Comments and suggestions are welcome !!!
- Voodoo Guru
- VooDoo Site Admin
- Posts: 719
- Joined: Wed Feb 23, 2005 8:47 am
- Location: Down there on the right...
Excellance!
Howdy Daniel,
Welcome to the Forum!!!
EXCELLENT Article Daniel!
That is what were talking about, true Experimentation!
That is incredible research and modification.
Thank You for posting it on the Forum.
This will help many people to have an alternative transceiver to play with eSSB.
We are honored to have you as a Member.
Thank You again for your contribution to this fine facet of Amateur Radio.
This Thread will be Sticky Posted to the top of this Topic.
Take Care,
Welcome to the Forum!!!
EXCELLENT Article Daniel!
That is what were talking about, true Experimentation!
That is incredible research and modification.
Thank You for posting it on the Forum.
This will help many people to have an alternative transceiver to play with eSSB.
We are honored to have you as a Member.
Thank You again for your contribution to this fine facet of Amateur Radio.
This Thread will be Sticky Posted to the top of this Topic.
Take Care,
Voodoo Guru
From Deep in the IDD of the Sub-Harmonix Realm
From Deep in the IDD of the Sub-Harmonix Realm
Is anyone out there capable and experienced to do this. My Icom is my only radio so a decent turnaround would be nice. And what would be a price on this job. I'm good at soldering just not good with soldering at the critical scale. I could just send u the Dsp board if that's all that's needed for the modification. Thanks! Very interested in equipping my icon with this.
Hi K9JPD,
I'll be glad to help, the mod takes only a few minutes if you know what components to change, but I'm afraid it will be way too overkill to send the board to Spain and back to USA just to change a few passives.
I'm pretty sure you can find some local experienced technician that, after viewing the document, can perform the mod quickly and for little money. I'll be glad to help him if there is something unclear.
Best regards,
Daniel.
I'll be glad to help, the mod takes only a few minutes if you know what components to change, but I'm afraid it will be way too overkill to send the board to Spain and back to USA just to change a few passives.
I'm pretty sure you can find some local experienced technician that, after viewing the document, can perform the mod quickly and for little money. I'll be glad to help him if there is something unclear.
Best regards,
Daniel.
Hello voodoo audio crew
I've got an Icom 756(non pro) to mod to get the voodoo audio.
My current set up is
PR 40
W2IHY 8 Band EQ
EQ Plus
Ranger 2950 DX
Sounds good and get good reports but need/addicted to the TX/RX Bandwidth
for that voodoo audio sound.
New set up will be to start with (hope config is right)
PR 40
MIC2200
DEQ2496
Ibox
Icom 756
I'm connecting the ibox audio out cable via the back of the Icom through the
ACC1 as suggested here .
I've got the DEQ2496 set up, thanks to all the info here and on the web but
could someone please give me basic starting settings for the MIC2200 if
possible.
I've brought some Starquad Canare cable and XLR connectors as I'm wanting to
make my own cable lengths with .001uf capacitors as suggested but not sure
on the exact .001uf capacitor to use and if you solder one capacitor
for every pin/shield. Could someone provide me the info with the right capacitor to use, a pic or diagram of the XLR cable connector made would be appreciated.
Any info or help would be appreciated and gratefully received.
Cheers
Bob
I've got an Icom 756(non pro) to mod to get the voodoo audio.
My current set up is
PR 40
W2IHY 8 Band EQ
EQ Plus
Ranger 2950 DX
Sounds good and get good reports but need/addicted to the TX/RX Bandwidth
for that voodoo audio sound.
New set up will be to start with (hope config is right)
PR 40
MIC2200
DEQ2496
Ibox
Icom 756
I'm connecting the ibox audio out cable via the back of the Icom through the
ACC1 as suggested here .
I've got the DEQ2496 set up, thanks to all the info here and on the web but
could someone please give me basic starting settings for the MIC2200 if
possible.
I've brought some Starquad Canare cable and XLR connectors as I'm wanting to
make my own cable lengths with .001uf capacitors as suggested but not sure
on the exact .001uf capacitor to use and if you solder one capacitor
for every pin/shield. Could someone provide me the info with the right capacitor to use, a pic or diagram of the XLR cable connector made would be appreciated.
Any info or help would be appreciated and gratefully received.
Cheers
Bob
Hello Bob,
Just a tip on the ACC1 audio: The rig, as it is, will give you a low audio fidelity through this connector, as it is intended for digital-like signals only. On the MAIN UNIT board there is an opamp (IC503b) which works near saturation and also has some high-pass filtering on it. I've changed a few components on my rig to get high-fidelity audio though ACC1 and this required to remove the whole board form the rig and change two or three SMD resistors and capacitors... It's not and easy mod... I suggest you do it only if you're comfortable with this level of hacking.
Anyway, with the mod I described you'll get quite some bandwidth just using the front mic connector. The ACC1 audio is better, yes, but not so noticeable.
By the way, if you transmit on AM, I suggest to increase R426 to at least 4.7kOkm (in order to get similar TX audio gains on AM and SSB) and to reduce R449 to 7.8KOhm or so (to get full 100% AM modulation depth without reaching the opamp positive output rail). Both are on the DSP board. Otherwise, if your rig is as mine, you won't get a decent audio level on your AM transmission.
Good luck!
Just a tip on the ACC1 audio: The rig, as it is, will give you a low audio fidelity through this connector, as it is intended for digital-like signals only. On the MAIN UNIT board there is an opamp (IC503b) which works near saturation and also has some high-pass filtering on it. I've changed a few components on my rig to get high-fidelity audio though ACC1 and this required to remove the whole board form the rig and change two or three SMD resistors and capacitors... It's not and easy mod... I suggest you do it only if you're comfortable with this level of hacking.
Anyway, with the mod I described you'll get quite some bandwidth just using the front mic connector. The ACC1 audio is better, yes, but not so noticeable.
By the way, if you transmit on AM, I suggest to increase R426 to at least 4.7kOkm (in order to get similar TX audio gains on AM and SSB) and to reduce R449 to 7.8KOhm or so (to get full 100% AM modulation depth without reaching the opamp positive output rail). Both are on the DSP board. Otherwise, if your rig is as mine, you won't get a decent audio level on your AM transmission.
Good luck!
Link no longer available?EA3HRU wrote:Now I can, so here it is!
http://petrus.upc.es/dfernan/personal/h ... h_Mods.pdf
Comments and suggestions are welcome !!!
===================
>> Livin' la VooDoo Loca <<
===================
>> Livin' la VooDoo Loca <<
===================
Hi Daniel
The modifications you have done on your Icom 756 require a lot of skill and knowledge. Unfortunately I myself can't do what you can do. So I'm going to have to buy another radio more set up for ESSB for myself because that last hacking mod on the main board for the acc1 fidelity audio is to complex for me and here in New Zealand not a lot of people are on hand to do what's required.
Thanks for all the info, it will most probably help a lot of other operators that can do these mods to get the voodoo in there audio with the Icom 756..
Cheers
Bob
The modifications you have done on your Icom 756 require a lot of skill and knowledge. Unfortunately I myself can't do what you can do. So I'm going to have to buy another radio more set up for ESSB for myself because that last hacking mod on the main board for the acc1 fidelity audio is to complex for me and here in New Zealand not a lot of people are on hand to do what's required.
Thanks for all the info, it will most probably help a lot of other operators that can do these mods to get the voodoo in there audio with the Icom 756..
Cheers
Bob
- Voodoo Guru
- VooDoo Site Admin
- Posts: 719
- Joined: Wed Feb 23, 2005 8:47 am
- Location: Down there on the right...
PDF Mod
Howdy Daniel,
We've added your PDF Mod to our server and changed the link in your original Post.
So to all of those who were looking for the mod, the link in the original post above now works.
It is also posted here for your convenience...
http://wz5q.net/docs/ea3hru_ic756_rx_an ... h_mods.pdf
Take Care,
We've added your PDF Mod to our server and changed the link in your original Post.
So to all of those who were looking for the mod, the link in the original post above now works.
It is also posted here for your convenience...
http://wz5q.net/docs/ea3hru_ic756_rx_an ... h_mods.pdf
Take Care,
Voodoo Guru
From Deep in the IDD of the Sub-Harmonix Realm
From Deep in the IDD of the Sub-Harmonix Realm
To EA3HRU Daniel.
I am making some mods on IC756 now.
You wrote (Wed Mar 04, 2015 7:19 pm ) this:
Just a tip on the ACC1 audio: The rig, as it is, will give you a low audio fidelity through this connector, as it is intended for digital-like signals only.
On the MAIN UNIT board there is an opamp (IC503b) which works near saturation and also has some high-pass filtering on it. I've changed a few components on my rig to get high-fidelity
So, what did you do?
What radio parts did you change around IC503b opamp?
Can you give more info?
With Best Regards,
Gary EW1MM.
I am making some mods on IC756 now.
You wrote (Wed Mar 04, 2015 7:19 pm ) this:
Just a tip on the ACC1 audio: The rig, as it is, will give you a low audio fidelity through this connector, as it is intended for digital-like signals only.
On the MAIN UNIT board there is an opamp (IC503b) which works near saturation and also has some high-pass filtering on it. I've changed a few components on my rig to get high-fidelity
So, what did you do?
What radio parts did you change around IC503b opamp?
Can you give more info?
With Best Regards,
Gary EW1MM.