Hello all, sorry for the offtopic (but these relais can be used also for a PA...). I want to build an antenna crossover switch for two radios and six antennas and I have some 30A DPDT relais (the typ
Guido The contact current rating should be derated for rf. I don't by how much for this relay, but a vacuum relay I have derates a 30A contact to 6A at 32MHz. In the vacuum relay heat cannot escape s
Guido, Relays not rated for RF are a very complicated matter. First, they are rated to hot switch at the current listed. But at radio frequencies there are often standing waves when hot switched or t
Thanks to all for the answers. The things are changed, because now I have twelve SPST W2W vacuum relais like this: http://tinyurl.com/37uv8r So, I changed my schematic to this one, with only six 30A
I do not think that you have to worry about the ratings of the 30A relays, but to be sure you are better to make an actual RF current carrying test to check for heating of the relay contacts. The rea
Guiado, First, I have never seen in single case in all the hundreds of relays I have tested at high power RF where the contact RF behavior is an issue. Sometimes the contact support, which can be ste
No matter what the relay, the actual contact area that touches is very small. The big area gets rid of heat however. This has to be. Otherwise coil voltage would affect contact pressure. That would
I saw a lot of these relays at Friedrichshafen for Euro15 last weekend. David G3UNA _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/m
Thanks Tom and Karl-Arne for the informations. I know that the relais are too much, but using only the vacuum SPST would be too risky: 1500W into receiver if some failure happens... What do you sugge
I cannot understand why you need a big vacuum relay unless switching speed is a problem, or why you need a 30 ampere relay. Even a relay like a Tyco RTD140 series will handle 5-10 kW at HF if you do
Hi Tom and all, thanks for your suggestions. I tried the relay with this ugly setup with dummy load on moving contacts, using MiniVNA: http://www.hamlan.org/maco/s66_test.jpg The SWR graph is this (1