THT Silver Mica and T50 Low Pass filter components for WSPR-TX_LP1
This is a bag with four pcs of Silver Mica capacitors and three Toroidal Iron power cores and magnet wire to wind on the cores.
One bag enables you to build a 7-pole low pass filter that removes the overtones on a low power transmitter for a specific frequency band from 3.4MHz up to 70MHz.
These are suitable for the WSPR-LP1 transmitter or for other home made transmitters with up to 200Watts output power on most bands. (see this link for more info on output power).
A low pass filter built with these components will typically have less than 0.5dB loss at the intended pass frequency and about 48dB suppression on the second and third overtone frequencies.
When used with the WSPR-LP1 all overtones will be below 50dBC witch meets or exceeds the regulatory standards in most counties for overtone suppression on the HF bands
The Toroidal cores are T50 (0.5 inch in diameter) by Amidon.
The Capacitors are from different but well know manufactures like Cornell Dubilier and are of Silver Mica type for lowest loss.
The magnet wire included is 0.4mm (AWG26) and the coating is heat strippable.
To prepare ends for soldering burn the ends with a flame and scrape of the residue with a knife.
See table for value of Capacitors and material of the Toroid.
Please note that in some cases a single value might be replaced by two capacitors in parallel. The WSPR-TX-LP1 has place for paralell caps on board.