My AR8200Mrk2B Started having sensitivity issues soon after I got it in late 2001. I have read that the 8200 was just not that good on the HF bands so I wrote my issue off. However, after finding I was having a problem selling a 8200 for anything close to the depreciated value because serious DXers have not spoken well of the unit, I decided to look into why the 8200 was not a good HF radio.
The unit needed about 300uv to make audio on the speaker as measured with the sig-gen. I opened the radio, placed it on the bench in a position to look at the RF board and started testing. I found that the unit was making audio at 2uV, close to the rated measurement. That is when I found I was having a 75-50ohm connector problem. Resolving that, I found that the sensitivity was still intermittently going between 300uv and 2uv. That is when I found the hairline air gap on the BNC connector.
I assume the connector had been pressed together to allow a lower soldering temp threshold for the wire alone and later the connector was pressed shut. I removed the tin shield to gain access to the connector, heated the connector and soldered the black hairline crack shut. I re-soldered the shield and tested to confirm the repair. I also cleaned the BNC connector center pin while I was there.
Pics of repair are here -> http://www.vambo.org/pictures/AR8200Repair/
---warning---
Repair at your own risk! If you are not technical, don't proceed with the repair without help from someone able to perform surface-mount component level repair
Hope this helps someone!
Vambo aka-K0BO
The unit needed about 300uv to make audio on the speaker as measured with the sig-gen. I opened the radio, placed it on the bench in a position to look at the RF board and started testing. I found that the unit was making audio at 2uV, close to the rated measurement. That is when I found I was having a 75-50ohm connector problem. Resolving that, I found that the sensitivity was still intermittently going between 300uv and 2uv. That is when I found the hairline air gap on the BNC connector.
I assume the connector had been pressed together to allow a lower soldering temp threshold for the wire alone and later the connector was pressed shut. I removed the tin shield to gain access to the connector, heated the connector and soldered the black hairline crack shut. I re-soldered the shield and tested to confirm the repair. I also cleaned the BNC connector center pin while I was there.
Pics of repair are here -> http://www.vambo.org/pictures/AR8200Repair/
---warning---
Repair at your own risk! If you are not technical, don't proceed with the repair without help from someone able to perform surface-mount component level repair
Hope this helps someone!
Vambo aka-K0BO
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