Qf1a Audio Filter

Autek QF-1A User Manual - gmcotton.com

http://gmcotton.com/Ham_Radio/MISC%20Manuals/Autek/QF1A%20instructions.pdf

QF-1A AUDIO FILTER Your new audio filter is the product of several years of development by the originator of commercial active audio filters for shortwave communications (1972). Each filter is thoroughly tested twice before shipment. Please read the instructions carefully for best results, and save them for future reference. If

Autek research qf-1A ssb cw am audio filter peak notch

https://www.chicago-industrial.com/North-Chicago/New/Industrial/Woodworking/Autek-research-qf-1A-ssb-cw-am-audio-filter-peak-notch.html5

Autek research qf-1A ssb cw am audio filter peak notch. This unit is placed between your receiver and your speaker. Audio is processed to improve selectivity, remove annoying hetrodynes with an adjustable notch filter, and act as an adjustable low pass or high pass filter for all signals. Selectivity is adjustable down to a narrow 20 hz.

Autek Research SSB / CW / AM audio filter, QF-1A ...

https://www.youtube.com/watch?v=2GyAG0WCzQQ

Autek QF 1A | QRZ Forums

https://forums.qrz.com/index.php?threads/autek-qf-1a.378076/

Autek Research QF-1, Autek Research QF-1A, Autek Research RF-1

https://www.universal-radio.com/used/sold302.html

U239 Autek Research QF-1 $39.95 SOLD Audio Filter This Autek Research QF-1 audio filter features: Peak, Notch and Low Pass. Input is via a hard wired ¼ inch cable off the rear panel.Operates from 120 VAC. [05/06] UI69 Autek Research QF-1A $64.95 SOLD Audio Filter This Autek Research QF-1 audio filter features: Peak, Notch and Low Pass. Input is via a hard wired …

eHam.net

https://www.eham.net/reviews/view-product?id=756

Another place the QF-1A really performs is in processing the receive audio from my laptop when I run NX6T remotely on CW. I am not able to select the K3's different DSP filter algorithms @NX6T when I run remote. Instead, the QF-1A on the receive end is …

Autek Research SSB / CW / AM audio filter, QF-1A ...

https://www.youtube.com/watch?v=KPmjNhvF9uA

IC Audio Active-Filter QF-1 Amateur-D Autek Research;

https://www.radiomuseum.org/r/autek_ic_audio_active_filter_qf.html

The QF-1 audio filter is a 4 pole filter with Peak, Notch and LowPass functions; the frequency and selectivity are separately adjustable from panel controls; the QF-1 off switch does not bypass the filter, so when it is turned off don't get any audio at the output. Net weight (2.2 lb = 1 kg) 0.4 kg / 0 lb 14.1 oz (0.881 lb) Source of data.

QRP-L 991222: Re: Improved OPAMPS for linear audio filter ...

https://qrp.kd4ab.org/1999/991222/0003.html

> home constructed audio filters with current high performance chips with > the same pinouts. > > I would like to improve an older Autek Research QF-1A which uses two > LM348N or MC4741 chips. These are 14-pin plastic DIP chips with four > Opamp stages in each package. > > Finally, is this idea worth pursuing? Will the reduction in noise be