Tip 1 - ALWAYS check the rig prior to power-up

I got a decent deal on a complete RAY-152 setup which had a couple noted problems. Distortion on SSB; dim back light. After the rig was unpacked and visually inspected I put it in the lineup with an antenna connected and proceeded to test it out. The radio is spec'd at 150w PEP and whomever was using it prior had the power control (internal adjustment) set to almost DOUBLE this value. Yeah, that'll distort. Remove covers, start servicing procedure. Eventually I discovered the balanced modulator was allowing some BFO leakage, resulting in ~200mW carrier in SSB TX. Definitely noticeable to my area 10M buddies. Studying the schematics, I saw a SN16913 DBM used as a balanced modulator, similar to what Yaesu did in the FT-817. Unlike Yaesu, there is no Carrier Null pot included in said JRC circuit. I decided to inspect the board to see if it had simply been omitted, but my JST-135 doesn't have one either - and it's very clean (in proper tune).

Hmmph.

Removing the board suddenly revealed the nemesis of JRC - their choice of mechanical SSB/CW filters. These were packed with a foam substance which turns to a gooey mess and greatly affects the passband of the filters.

https://people.zeelandnet.nl/wgeeraert/koku/koku.htm

I've repaired at least ten of these things since acquiring my first JRC receiver so in I went. Better...but still some BFO leakage present. The radio went on my test bench, where extender cards were used to elevate the Filter Unit (CFH-38A) out of the card cage for inspection. Application of power resulted in Factory Smoke(TM) being emitted from somewhere behind the front panel.



See the "Phones" jack in the pic below (not my rig)? Somehow in a previous life it had been snapped off internally - and as luck would have it, the jack's Ground lug hit just the right place (the +9V rail for the front panel) to cause a filter choke to burn up and render the radio inoperative. Mind you, this rig passed the Rattle Test before I put it on the bench the first time.

When I disassembled the front of the unit to inspect things I found a couple more potential time bombs...but we'll address those as soon as the parts to fix this mess arrive. Also need replacement EL panels - and looks like I'll be making (trimming) my own.

wir.skyrock.net.jpeg