Help with AX-190 receiver, low volume and low signal

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W4AJF
Posts: 349
Joined: Fri Mar 21, 2003 3:57 pm

Help with AX-190 receiver, low volume and low signal

Post by W4AJF » Wed Nov 20, 2019 5:54 pm

Hi all, I acquired an Allied (Realistic) AX-190 receiver and volume is low ( turning AF Gain all the way up it's still low) and signals although they are there and clear don't really move the meter. When I hook up an amplifier for receive (HP461A) then signals come in loud and clear and move the meter. I changed the electrolytics in the power supply board and AF board but no change. I am hoping with the symptoms I have described someone out there may have experience with the AX-190 (or SX-190) and tell me possible what board and/or component(s) it may be. Please, if you are familiar let me know, I would greatly appreciate it.

Adam Farber W4AJF
Cooper City, FL

k9yli
Posts: 226
Joined: Fri Aug 12, 2005 11:35 pm
Location: northwest wisconsin

Re: Help with AX-190 receiver, low volume and low signal

Post by k9yli » Sat Nov 30, 2019 5:25 pm

first off, connect an audio signal to the center pin of the volume control.. and see if the out put is loud. Or just touch the center pin with your finger. if you hear a loud pop then the audio section is ok. Out put from headphone jack for a am portable radio with a capacitor in series for one lead to the control should work. Or clip in a mic to the center pin to ground.. that will turn audio into a PA amp.
the other half,,, is take a lead off the non ground side of the audio control and feed to a small audio amp
to substitute for the audio string in the radio..
Either test should tell you if its an audio amp problem or in the detector or rf amp area.
The schematic is essential to fix this problem.!!!!!!!!

You mentioned that with a pre amp the meter moved.. that might show that the problem is in the very early rf amp area . The IF and detector and audio section actually work as you do get useful signal
from the speaker when using pre amp..

W4AJF
Posts: 349
Joined: Fri Mar 21, 2003 3:57 pm

Re: Help with AX-190 receiver, low volume and low signal

Post by W4AJF » Sat Nov 30, 2019 5:43 pm

Hi, thanks for the post, I just found out that 2 mosfets needed to be replaced and that fixed the problem. I appreciate you taking the time. Adam W4AJF

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