Laurence you need to insert your BCI filter between relays K1 pin 12 and relay K3 pin 14. This will put your filter in the receiving path only.
Skip Davis, NC9O
toggle quoted message
Show quoted text
On Mar 13, 2019, at 18:31, Laurence Oberman <oberman.l@...> wrote:
Hello Gary
Thanks for pointing it out, right now its NOT only the receive path
but I am only transmitting at 3w.
But I will be replacing it once I have the filter built Jack suggested.
I looked at receive path only on the Ubitx schematic when I first got
it but I figured its surviving 3W, and has done so for a while now.
The issue with all the cheap SDR filters are they are meant primarily
for receive only. :(
On the nooelec page when I first looked at it it had this which is
misleading because 18dbm is not "higher power"
Anyway I know I am pushing it but its surviving cw at the moment and
still working.
I did not need it on the V4.
"
DC current handling is 250mA (min), and the maximum recommended signal
level is +18dBm (5Vp-p), so there is no issue using the filter for
higher-power applications. Typical performance characteristics can be
found on the downloads tab of the product page on our website.
"
Thanks a lot for pointing it out as others would have not realized the
limitations.
Regards
Laurence
On Wed, Mar 13, 2019 at 6:17 PM Gary Anderson <gary.ag5tx@...> wrote:
Laurence,
You have this filter installed in a receive only path, correct? When you made a statement of inline and 'can handle the power easily' a caution flag went up.
Amazon / Nooelec Filter is rated for 5V pk-pk / 2.5V pk / 63mW. Primary concern is the components (especially caps) are not rated to the required voltage to be suitable in the transmit path.
Regards,
Gary
Skip Davis