As I’ve previously mentioned, the Xiegu X6100–at least at time of posting (January 17, 2022)–has overloading issues. If you listened to the activation video I posted yesterday, you can hear a local AM broadcaster punching through the 40 meter band, especially noticeable before/after operating SSB.
Several subscribers asked if I tried using the attenuator and RF gain to mitigate the level of overloading. Attenuators and RF gain can be an effective means of mitigating noise levels, but they essentially affect everything on the band–all signals somewhat equally.
A better approach is to use a BCI Filter.
BCI filters reduce or notch out AM broadcast band signals so that they don’t overload your receiver.
BCI Filters are placed between the radio and the antenna. They can have a dramatically positive effect if you live near a broadcast station and/or if you have a radio that’s prone to overloading.
I see them as a more “surgical” approach to solving broadcast band interference.
BCI filters are simple, inexpensive, and effective. Here are two options shared by QRPer readers:
BCI Filter: Homebrew Option
Thomas, I’ve attached a picture of the QRP BCI filter I built prob close to 20yrs ago. It is a must at my QTH where the “Score” a megawatt am station is within 10 miles of me.
The X6100 in my setting is not usable without the filter.
The attached videos show with and without the filter monitoring a CW QSO. You can see the time on the radio to confirm they were filmed approximately at the same time.
Rich couldn’t find the exact plans for this particular BCI filter since it had been so long since he constructed it, but he pointed to this article for reference.
Thank you so much, Rich for sharing this.
Note that BCI filters are also available as kits. You can find them for as low as $5 and they’re quite simple to build; they will require winding a few toroids. Simply do a search for “BCI Filter Kit” and you’ll find several results.
Make sure you’re purchasing a filter kit that can handle a transmitted signal. This is typically indicated in the description.
If you’ve recently built a BCI filter (homebrew or kit) please share details and links in the comments!
BCI Filter: Off-The-Shelf Option
Our thanks to Dennis (K2DCD) who writes:
I know shortwave listeners who swear by their ICE filters and I agree that they are excellent quality.
Of course, make sure you’re purchasing either the Model 400X which attenuates everything below 3.5 MHz, or the Model 402X which attenuates everything below 1.8 MHz. Both are $42.00 US. The other models are less expensive, but designed for receiving only.
Many thanks again to Rich and Dennis for sharing their tips! Please comment with details if you use a BCI filter at home and/or in the field.