Search found 9 matches

by EA3HRU
Sun Jun 10, 2018 1:38 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

Hi Gary, I didn't keep notes on that, but by looking at the schematic of the radio I should have replaced R581, R518 and R519 by 10K, R526 by 1K and C520 by 2.2nF. I remember that I had to remove the board from the radio as the components were on the bottom side. All these on the main unit. By the w...
by EA3HRU
Sun Jul 09, 2017 11:48 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

Hi,

I don't really know, check on the schematic if they're based on the same filter chip. If they're you may have a chance!

Best regards,
Daniel.
by EA3HRU
Mon May 11, 2015 6:06 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

Hi,

You cannot put decent analog audio through ACC without changing a few components on the bottom of the Main Unit board. This requires removing the board from the radio. This is independent of increasing the TX audio bandwidth, you still can use the front mic and go wide...

Good luck,
Daniel.
by EA3HRU
Mon May 11, 2015 1:34 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

Hi,

I don't remember exactly, but it was between 10nF and 100nF. I only used them to block the DC component coming from the radio, otherwise the filter shorts it out to ground. Nothing fancy like impedance matching or so...

Best regards,
Daniel.
by EA3HRU
Sat Mar 07, 2015 1:16 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

Hummmm. It appears that the whole server is down.... I don't have access to other stable web server, so anyone needing it, send me an email to daniel_at_z-ha-dum_dot_dyndns_dot_org . Te file is free to share, so if anyone can post it on the web, feel free to do so.

Daniel.
by EA3HRU
Wed Mar 04, 2015 4:19 pm
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

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 chan...
by EA3HRU
Mon Nov 18, 2013 9:22 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

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 view...
by EA3HRU
Wed Aug 07, 2013 3:55 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

Now I can, so here it is!

http://wz5q.net/docs/ea3hru_ic756_rx_an ... h_mods.pdf

Comments and suggestions are welcome !!!
by EA3HRU
Wed Aug 07, 2013 3:53 am
Forum: Modification Maddness
Topic: Icom 756: Increasing the TX and RX Audio Bandwidth
Replies: 20
Views: 35684

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 thi...