LOW-PASS FILTER FOR 2 TONES GENERATOR

Here is a 2 tones RF generator for 7030 and 7050 kHz, sold by funkamateur.de :

https://www.box73.de/product_info.php?products_id=3847

 

As harmonics are present at the output, a low-pass filter is required.
 

Good harmonics filters for amateur radio bands can be found at the G-QRP web site, good up to 10 Watts and low insertion loss :

www.gqrp.com/Datasheet_W3NQN.pdf

The PCB filter fits in a 80 x 25 x 25 mm enclosure sold by SV1AFN 

https://www.sv1afn.com/enclosures.html

The filter with 3 x T37-6

The result after tweaking the inductors :

Return loss @ 7050 kHz is 22 dB, SWR = 1.17