Hello everyone,
its been a while since my last post. There were a lot of things which kept me from posting an update.
Nevertheless, I finally managed to do some measurements of my relay replacements. The VNA at work was blocked all the time. Therefore, I had to find a different way to measure the relays. In the Album there are now the measurement result of almost all possible combinations you can have in a DPDT relay.
/g/TekScopes/album?id=299851All in all the replacements perform quite a bit worse than the originals. This is not surprising as the original relays are close to perfect in terms of HF coupling (tiny cross sections with relatively large gaps between adjacent parts). The PCB in contrast provides 'long' traces in parallel.
As the VNA was not available I had to measure the relays with a automated setup composed of my 60MHz function generator as signal source and my digital oscilloscope as measurement device. Due to the noise floor of the oscilloscope and the low output level of the funtion generator dynamics of the measurement was not crazy high.
To get an impression how much coupling would be possible at the given distances between pins, I always measured one complete trace without any DUT at all (the traces called 'Fixture').
Nevertheless, the measurements always show that the replacement performs not as good as the original relay, but I think this is the price you will have to pay to get a relaibly switching relay.
Regarding leckage current I will try to perform a few measurements to see if the required 0.2nA is achivable or not. I hope the next update will not be delayed as much as this one.
Right now I have 4 unpopulated panels left over (each with 36x 148-0034-00 and 30x 148-0035-00 relays). Plus some additional ones of the first panel which were already populated with SMT components.
If you are interested, send me a message off list with your needs and we can discuss how I can help you.
Best regards,
Wolfgang
