[Premium-Rx] Cubic 3030 - need power supply module

Tue May 31 22:12:37 EDT 2011

Hi Cubic R3030 Drivers, (R2411 &R3050 hang circuit is gone)

Here is the simple modification to eliminate the AGC hang circuit. When I was done and I listened a bit maybe the issue is C66 is too large causing a big delay in the AGC and R92 a 22K the discharge resistor is too small but I didn't go back and check. This change gives you about the same discharge time constant .05, .25, 3.0 sec.
1. Remove Q14 AGC discharge FET (controlled by U6B -12 one shot )

2. Remove R91 a 1Meg resistor between U6B-7 and VCC.

3. Install the 1 MEG resistor across the outside pads of Q14 (Drain -Source) This is the new AGC discharge resistor

4. Drill out plated through hole or cut trace at R91 U6B-7 side (to get oneshot out of circuit,)

5. Connect jumper U9 4066 pins 9-10 to pin 7. (grounds new timing caps)

6. Remove C66 33uf/25V near U9 (old AGC storage cap not necessary)

7. Connect jumper C66 positive side pad to the bottom side board from R91 connected to C28-.047uf, C67-.22uf and C68-3.3 uf positive side. (These are the new AGC timing caps.)

The .05 and .25 AGC positions are pretty active so you might want slower settings it is easy to modify by changing the cap values. There is a lot of static tonight and .05 really catches the static peaks. A bit fast for SSB. 3.0 seconds sounds fine.  Pretty easy to back out depending on how you break the connection to U6B-7.  Timing .05= C28 &1Meg,  .25= C28+C67 &1Meg,   3.0= C28+C68 & 1Meg
--------------------------------------------------------------------------------------------------------
AM Agerage Cubic increased C65 to 10uf in later receivers. The value in my module is 2.2uf. I like the higher value better.

Frank WA1GFZ

From: Tim Kass <timkass at hotmail.com>
To: premium-rx at mailman.qth.net
Sent: Monday, May 30, 2011 9:17 PM
Subject: [Premium-Rx] Cubic 3030 - need power supply module

Hello group, well was listening to 40 meters yesterday when suddenly the receiver stopped playing and went dark...the toggle switch also switched itself to the OFF position automatically, didnt know it could do that.  Trying to rest the power supply module did nothing and I get no module fault lights on any of the modules...guessing they are not getting power.. so looking for any advice or likely a new/used power supply module.. have not swapped out the other side of the receiver as a friend is borrowing those modules to get his Cubic up and running.. thanks in advance..

73, Tim K8WBL

"Everything you need is inside you, All you fear is there as well"

______________________________________________________________
Premium-Rx mailing list
Home: http://mailman.qth.net/mailman/listinfo/premium-rx
Help Page: http://mailman.qth.net/mmfaq.htm
Post: mailto:Premium-Rx at mailman.qth.net
Help Contact eMail:  paul at 8zo.com
Home Page:  http://www.premium-rx.org/