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Gordon Gibby
开云体育?Jerry, I'm with you, my plan is #4 with through-hole relays and surface mount capacitors / inductors as needed.? ?I don't need the higher bands that much and this is such a cool transceiver touse for winlink / ale / etc that these pesky issues just have
to be fixed.? ?The first time I put it cycling ALE those folks were AMAZEDthat I could scan all their frequencies well.? The bandpass of my crystal filter was a bit too narrow, but now yall have taught me how to fix THAT as well and I'll do that to some rig.?
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Cheers, gordon
From: [email protected] <[email protected]> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Friday, August 10, 2018 1:10 PM To: [email protected] Subject: Re: [BITX20] Harmonics ?
Kees,
A few options that come to mind: ? 1) Add external box with switchable filters ? 2) Remove relays, create daughterboard to replace relays and LPF's plus additional relays at the far side ? 3) Cut up current traces, add straps at board edge, use current relays only at input to LPF ? 4) Same as above, but add a daughterboard with just the 3 extra relays at the board edge ? 5) Clean up what goes into the final somehow so the LPF's don't see so much crud ?? My current favorite: ? 6) Cut up the traces, dead bug three surface mount relays to the bottom of the board between L13,16,19,22, ? ? ? power the coils from the same source as the corresponding relays at KT1, KT2, KT3 The surface mount relays are a bit more expensive than the high-volume through hole relays. Mouser?80-EE2-12NUX-L is $1.95 quantity one, down towards $1.00 in volume. At 10.35mm high, they are just a hair shorter than the board standoffs provided with the uBitx, at 7.5mm wide they fit nicely in the space available.? (There are smaller relays at extra cost.) A grand total of $6 for an individual to clean up all but the (45mhz-FOp) spur on 15m-10m. The coils can be powered from the same drivers as the existing relays, ? user will see no difference once the rig is put back in the enclosure.? Jerry, KE7ER On Fri, Aug 10, 2018 at 08:43 AM, Kees T wrote: Do you have a summary of the various options available ? or being worked, with pros and cons ? or do we just wait for a "Eureka" thread ?? |
