This product is made to order by Spectrum Communications. It is not ready built waiting for dispatch.

SEND A BUYERS NOTE THAT YOU WANT EITHER 50 Ohm , or 820 Ohm TERMINATION.

This is a 6 crystal ladder filter with a 50 Ohm or 820 Ohm & 4pF IN/OUT termination.  

Input and output are via a 4:1 ratio wideband transformer one side of which is grounded.  The filter in the photograph has been carefully measured and found to have a centre frequency 300Hz low at 8.999700MHz.  The carrier crystals required to go with this would need to be adjusted for 8.9982MHz for USB and 9.00115MHz for LSB corresponding to the -20dB points on the characteristic.

The screen shot has horizontal squares of 1kHz width and the vertical scale is 10dB per division.
The -60dB bandwidth of 5.56kHz divided by the -6dB bandwidth of 2.4kHz gives a shape factor of 2.29:1, really impressive.  Insertion loss is less than 4dB and the stopband within the test jig is 70dB.  PCB size 60x27x18mm.

This has been created as a repeatable filter product with a specially chosen crystal frequency to give the required bandwidth with a centre frequency as close as possible to 9.000000MHz.  A change of the ladder loading capacitors for a wider bandwidth results in a higher centre frequency.  With the loading applied to this filter the -6dB bandwidth is 2430Hz.

It can be used in an 80m & 20m SSB Receiver using a single 5.0-5.5MHz Local Oscillator as shown in the block diagram.

Also available:
RX 9MHz IF Amplifier & AGC, Ebay 2837 2819 5874.
SSB Detector & 9MHz Carrier Oscillators, Ebay 2840 1411 9328.
Audio 1W TBA820M Amplifier, Ebay 2837 2603 9697.