I found a Low Pass Filter board out of a TS-940 Kenwood on ebay for $20. It's good to 100W, selectable via 3 digital lines in 7 bands. The only downside is it's a 24v board. The bands are:
1.5 - 2.5
2.5 - 4.5
4.5 - 7.5
7.5 - 10.5
10.5 - 15.5
15.5 - 22.0
22.0 - 30.0
Oh, and it has FWD and REF outputs on it as well. I've seen many of these filters going for anywhere between $15 and $100 (the ones for $100 rarely sell) and are usually no problem to connect to your project.
Vince - K8ZW.
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On 09/23/2018 01:58 PM, Gordon Gibby wrote:
Very cool.
I plan to get external filters for the 160 m band.
Or, since I really don¡¯t use the higher bands, maybe switch them around a bit.
Neat little rig, will do all kinds of cool things for me.
On Sep 23, 2018, at 13:31, Bill Cromwell <wrcromwell@...> wrote:
Hi Allison,
Little details seem to need a lot of refreshing here - as you often point out. I am using my uBitX on the air primarily for CW up through 17 meters (but no QSOs higher than 14 MHz so far). I use an external filter and will be using a better one (more convenient for field portable use) while I am working on an internal fix. Yes, one of the mods. I just got the board when I returned from a vacation.
The external filters might be a good idea even with internal mods to reduce trash even more. The external filters are pretty much painless AND being external may be re-used with other radios:) It's nothing new. Hams have been using them since the 40s or 50s - maybe earlier.
I am also (ab)using my uBitX as bench test gear :) I used it to identify broken parts in a PFR-3 and make the repairs. Two inductors had fractures in their windings and one transformer was installed backward! The uBitX with a scope probe where the antenna normally goes made the 'divide and conquer" process quick and easy. It served as a $120 signal tracer. And then I re-used my signal tracer as a two way radio :)
73,
Bill KU8H
On 09/22/2018 10:41 PM, ajparent1/KB1GMX wrote:
Doc sees horse,
He's dead Jim!
Spurs are less an issue for 20M and below.
External low pass or transmitting band pass filters are responsible way
to go.
Allison
--
bark less - wag more
--
Michigan VHF Corp.
