HobbyPCB.com

Built by Hobbyist for Hobbyist!
It is currently Wed Aug 21, 2019 10:58 am

All times are UTC - 5 hours




Post new topic Reply to topic  [ 13 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Fri Aug 19, 2016 11:41 am 
Offline

Joined: Wed Dec 17, 2014 4:09 am
Posts: 3
Hello, GE to Everybody!

I am using the Hardrock-50 PA together with the ELAD FDM DUO SDR radio. Recently I noted a strong noise induced into the ELAD FDM DUO by the Hardrock-50 that completely disappear if I switch off the Hardrock-50 or if I disconnect the coax from the ELAD to the HARDROCK -50. This make me conclude that the noise is generated inside the HARDROCK-50, may be by the clock of the uControllers, and go out to the ELAD through the central pin of the coax. Is there someone who experienced the same problem and how to cure it? Thanks in advance for the help.

73 de Leo, I3RKE.


Top
 Profile  
 
PostPosted: Fri Aug 19, 2016 3:50 pm 
Offline

Joined: Sat Jul 23, 2016 3:41 pm
Posts: 16
Hi Leo,

Is the Duo running solo or do you have a computer connected?


Top
 Profile  
 
PostPosted: Fri Aug 19, 2016 5:41 pm 
Offline

Joined: Mon Jul 23, 2012 6:25 am
Posts: 1143
Also, do you have any ground wires on the Elad and/or the HR50? Is the noise on all frequencies? The microprocessors in the HR50 and ATU use the on-chip oscillator blocks for very low EMI. There are no external oscillators. The HR50 runs at 40 MHz and the ATU is running at 64 MHz both of which shouldn't cause trouble in the Ham Bands.

My ELAD is on the way so I can set it up and try it myself. I'll also be working on an automatic band changing solution for the Elad-HR50.

Jim.


Top
 Profile  
 
PostPosted: Sun Aug 21, 2016 4:50 am 
Offline

Joined: Wed Dec 17, 2014 4:09 am
Posts: 3
Hello,
my ELAD DUO is running stand alone. I'll check gain and carefully the connections of the coax cables on the MOLEX connectors. May be one of the screws get loose ! I'm happy with the couple made up with ELAD DUO and Hardrock-50. Concerning the automatic band switching I have a solution, but not for all the bands! It is made using some signalling coming from DUO to drive a preselector

Ciao and 73, Leo I3RKE


Top
 Profile  
 
PostPosted: Sun Aug 21, 2016 4:56 am 
Offline

Joined: Wed Dec 17, 2014 4:09 am
Posts: 3
Hi Jim,

the noise is at selected frequencies on all the bands and there is no ground connection.
Tnx for your reply.

73 de Leo, I3RKE.


Top
 Profile  
 
PostPosted: Sun Aug 21, 2016 7:56 am 
Offline

Joined: Mon Jul 23, 2012 6:25 am
Posts: 1143
Hi Leo,

Out of 700+ amplifiers you are the first to report hearing any noise at all while connected to the HR50 so we're in new troubleshooting territory! What kind of power supply do you have running the HR50?

Jim


Top
 Profile  
 
PostPosted: Sat Sep 16, 2017 9:24 pm 
Offline

Joined: Sat Sep 16, 2017 9:03 pm
Posts: 4
Hi,
Have there been any findings on this? I have the same issue with my HR50 (#1814, HW:G, FW:3.0D, ATU:1.4) and FT-817ND. With only a dummy load connected to the 50, I can hear noises on certain frequencies in multiple ham bands mostly 20m and above. In my case, the strongest noise is around 21.260MHz (signal strength 7) and weaker ones at almost every 60KHz up and down that frequency. If I turn off the 50, they disappear. Everything else works great. I use an old transformer power supply which is unlikely to generate digital noise. No PC is connected.

Kay Ishikawa
JI1BQW


Top
 Profile  
 
PostPosted: Sun Sep 17, 2017 7:28 pm 
Offline

Joined: Mon Jul 23, 2012 6:25 am
Posts: 1143
What kind of power supply are you using to power the HR50? Try using a battery, the current draw is minimal during RX.

When the HR50 is in the RX mode, unless you have the QSK board, there are no active components in the RX path, only relay contacts.


Top
 Profile  
 
PostPosted: Tue Sep 19, 2017 7:48 am 
Offline

Joined: Sat Sep 16, 2017 9:03 pm
Posts: 4
Hi,
Thanks for the reply. I tried with a battery but it didn't make a difference. The noise are still there. I have the QSK in it. What"s the easiest way to disable the QSK?


Top
 Profile  
 
PostPosted: Tue Sep 19, 2017 6:50 pm 
Offline

Joined: Mon Jul 23, 2012 6:25 am
Posts: 1143
If you pull off the front panel but leave the power switch plugged in and turned on, the QSK will still be biased in RX but the microprocessor will be off. The only oscillators in the amplifier are the PIC microprocessor and it runs at 32 MHz and the USB running at 12 MHz.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group