Heatsinks are falling off in 6400 and 6600 models.

Mike-VA3MW

Doug, I am not sure I understand, but this is not a firmware issue.

Mike

Douglas Maxwell

Have a look at Gerald Youngblood’s last post on this issue. I read this as the correct fix was in firmware but this being too expensive, a heatsink was placed on the ADC to sort an interface timing issue between the ADC and the Virtex 6 FPGA. The rx noise level jumping is all about this interface timing and how ADC samples are captured by the FPGA. Putting a heatsink on the ADC changes the interface timing for the better, but now the interface is more susceptible to temperature changes. Have flex passed this solution through a temperature chamber through its entire specified operational temperature range paying particular attention to rx noise floor levels?

Tim - W4TME

You misinterpreted Gerald's comment. When the ADC runs too hot, two things occur; the dynamic range of the ADC decrease (there is a linear relationship between DR and temperature) and the clocking of the chip changes too.

If the thermal issue with the ADC was not resolved by the upgraded heatsink, changing the FPGA code would not have fixed the dynamic range problem, it would have masked it.  That is why there is a wink emoji after his comment.

The new heatsink provides more thermal mass and more efficient thermal transfer than the previous components.  And yes, we have tested it and it meets our specs.

Douglas Maxwell

Thanks for the quick response Tim, I am encouraged to hear that this solution doesn’t compromise the specifications of the radio. The symptom of occasional raised noise floor due to odd operational temperature extremes such as field day, dxpeditions etc. as opposed to normal shack operation would be very hard to spot unless you deliberately set out to check for it with a dummy load and knew in advance what the typical noise floor should be. Thanks for this clarification.

Tim - W4TME

You're welcome, Doug.

WQ2H - Jim Poulette

Gerald,
The whole story? Maybe.

While the problem is clearly an annoyance, I really think you're being overly **** yourself here.
I've been an ME in electro-mechanics for decades, electronics, optics, mechanisms, motion control, the whole ball of wax - and it looks to me like the design side, at the time, had it basically covered. Could it possibly have been the "hand-off" to manufacturing engineering / manufacturing?

I've worked with these "PSA heatsinks" and what killed us was a lack of process control - making sure the mating surfaces were clean, consistent quality of the PSA, keeping the PSA itself clean and uncontaminated prior to installation, and of course environmental controls during assembly (humidity very bad....). The heat characteristics and tensile strength of the bond is pretty cut and dry. The process - maybe not so much.

Glad to hear it's been resolved - personally I love the PSA heatsinks. We use them sucessfully in many instruments, stationary and handheld. Maybe you have to come from the ole' EccoBond thermal epoxy days to really appreciate them.
73 Jim, WQ2H

N8SDR

I had one of those turds brand new , 1 month after I had it it went DEAF, sent back for repair, 32 days later it went deaf again, at that point I was really PO'ed having spent $2700 for a new rig and back to them twice within roughly 60 days, while there the second time, I called said I had a job transfer and to ship it to another address, when fixed,  as I had made a deal to trade it to another OP who had a Flex 3000 and wanted a knob radio, that was 9 years ago, and I still have that 3000 that works very well, when I did have questions Flex was very response and helpful, which is way I bought a new 6000 series. Everything by brand Y was removed from shack and will never enter it again. The FT-2000 had a terrible design flaw which if used near or around strong signals would **** the pre-amps in the front end, not to mention nothing on the rear panel was physically grounded to the case, it was all PC board component mounted and that alone was an RF issue. They never reached out to there customers and took care of that issue, instead they blamed them for misuse of the radio.