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Technical Topics => Equipment => Topic started by: Matt285 on October 14, 2019, 1628 UTC

Title: ICOM ATT issue
Post by: Matt285 on October 14, 2019, 1628 UTC
My Icom 718 is acting up. I have to turn the attenuator (ATT) on to be able to receive signals, which is the opposite way an ATT should work? Without the ATT on its very quiet. Checked all of the volume, gain, NB etc settings.
Title: Re: ICOM ATT issue
Post by: CoolAM Radio on October 14, 2019, 1717 UTC
Already try to do a RESET ?

If that doesn't solve the problem -

Google > "icom 718-ATT problem"
for more information!

Goodluck!

André
CoolAM Radio - Shortwave
the Netherlands
Title: Re: ICOM ATT issue
Post by: Matt285 on October 14, 2019, 1729 UTC
Yes. i should have mentioned I did the reset several times nad even left it in a closet for 2 weeks and reset again. Thanks
Title: Re: ICOM ATT issue
Post by: CoolAM Radio on October 14, 2019, 1847 UTC
Try >  ( just simple suggestions! )

- When set is ON - disconnect powercable
  Wait 15 - 20 seconds - then Switch Off the PWR button on the set
  After this - connect PWRcable again & Switch set ON
==========================================
- Same - but with the ATT Pressed In
  Wait 15 - 20 seconds - then Switch Off the PWR button on the set
   After this - connect PWRcable again & Switch set ON
==========================================
- If you have a 2nd transceiver-try ( disconnect antenna/coaxcable)
  set a carriersignal on a freq - and check what ATT is doing then
==========================================

If you're interested - I've several
Icom IC-718 information ( PDF ) files
(Manuals/Service-Manual/Updates/Mods etc.!)
@

http://www.mediafire.com/folder/tjvr8kemx0boz/ICOM_IC-718 (http://www.mediafire.com/folder/tjvr8kemx0boz/ICOM_IC-718)

(http://www.coolam.nl/images/cbham0.jpg)

Special LINK for More "CB-/HAM Radio"  http://cbhamradio.tk (http://cbhamradio.tk)

André
CoolAM Radio - Shortwave
the Netherlands
Title: Re: ICOM ATT issue
Post by: Matt285 on October 14, 2019, 2012 UTC
Thanks for the new suggestion Cool AM. Tried it a few times in the way you suggested. No improvements. Definitely worth a shot though. At least i can listen to shortwave for the time being. Not all is lost. Would love to transmit though. Maybe I'll fire up my QRP rig on 40m later. 
Title: Re: ICOM ATT issue
Post by: CoolAM Radio on October 14, 2019, 2030 UTC
You're welcome!

And.. not tried is always missed.. ( or something like that! )

I guess it's some sensitivity problem.....................

Maybe send email to Icom Service center?


Goodluck!

André
Title: Re: ICOM ATT issue
Post by: Josh on October 14, 2019, 2040 UTC
Did you get a front end zap via the coax? Sometimes those will take out the section then active in the front end, leaving the attenuators intact, or if the atten was active when struck this section will be lost and the rest might be undamaged. If there's a known atten issue with the 718 then there you go.
Title: Re: ICOM ATT issue
Post by: Matt285 on October 14, 2019, 2221 UTC
I read about the front end static discharge issue. I have wood floors in my radio room, but it is entirely likely. What i meant by that is not having carpet cuts down on static a bit. I think?
Title: Re: ICOM ATT issue
Post by: Josh on October 14, 2019, 2329 UTC
I meant static coming down the coax such as from a nearby lightning strike. Shuffling your feet on a carpeted floor and touching the faceplate of many recent solid state rigs can make them go bonkers too.
Title: Re: ICOM ATT issue
Post by: Matt285 on October 14, 2019, 2332 UTC
I am always good about disconnecting my coax during the summer in particular. It had been good weather when this issue started. I will have to wait until I can afford to send it out for repair. At least I still have a receiver.
Title: Re: ICOM ATT issue
Post by: Josh on October 14, 2019, 2352 UTC
If you don't have a dc ground return from both sides of your dipole, assuming that you have a dipole, you might add one. They can be as simple as a 10kohm or greater resistor or a old choke. These may reduce noise on the antenna. Some baluns, particularly of the voltage variety, return dc at each terminal.

The cool kids use gas discharge arrestors, these nifty devices clamp anything over x voltage they come into contact with, equalising voltage betwixt inner conductor and outer shield in a nanosecond or two.
https://www.mfjenterprises.com/Product.php?productid=MFJ-270
Title: Re: ICOM ATT issue
Post by: Matt285 on October 15, 2019, 1914 UTC
Yes. Regardless of this particular issue i need to add some type of protection. Especially her in Florida
Title: Re: ICOM ATT issue
Post by: Josh on October 15, 2019, 1959 UTC
A  fun vid on 718 trouble shooting;
https://www.youtube.com/watch?v=y7zd3bzu60o