Manager


Manager - NA4M
Manager Notes

Reviews For: Autek Research QF-1A

Category: Filters, Audio: (DSP and others)

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : Autek Research QF-1A
Reviews: 34MSRP: No longer in production
Description:
SSB/CW/AM Audio & Notch Filter
Product is not in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
15344.9
K7FD Rating: 2022-11-11
Excellent signal boost! Time Owned: 0 to 3 months.
Recently acquired a QF-1A and can confirm it is a winner. After an easy conversion to 12 VDC (see manual for mod) I connected it to a variety of radios including the latest transceivers. It improved SSB and CW copy on all of them! I dare say it adds almost 10 dB to signal strength and intelligibility. Have yet to try it on AM but due to the inherently narrow bandpass of the device I doubt the results will be as dramatic.

I can see why others say they can’t live without the QF-1A! A big thumbs up…
K2JF Rating: 2019-10-19
big surprise Time Owned: 0 to 3 months.
I have a 756 Pro II and have used a West Mountain Radio ClearSpeech filter and that all worked well together. I thought I would give his Autek Qf-1A chance and was fairly blown away! Where to start? I read the reviews and a cw op I set the control to Peak and people suggested then tuned the frequency control to maximize the signal. Two things I noticed. 1) don't even need the rig's DSP any longer and 2) I can hear signals with the Autek on that I can't with the Autek off. Still getting to know it but it seems pretty incredible at this point in time. I keep bypassing the Autek to make sure I'm not dreaming.
K7LZR Rating: 2018-08-03
Very good filter! Time Owned: more than 12 months.
I found this QF-1A at a hamfest in fall 2012 for a good price and so bought it for use with my Yaesu FT-817nd. Got home, set it on a shelf and forgot all about it until just this week so it sat for nearly 6 years :).

Finally connected to the FT-817 and started to use it for interference combat.

I must say, this is probably the best filter system which I've had the pleasure to use. I also have an SDRPlay RSP-1A SDR receiver which of course has many, many filter options along with DSP, and the Autek QF-1A actually seems to dig signals out of the noise better in many instances.

It does take a bit of on-the-job training in order to get the most from the QF-1A but after a bit of familiarization & experience you will quickly come to appreciate just how effective it is.

For CW operation, the Peak filter is tops and easy to use - just set selectivity and then slowly rotate the frequency control until the desired CW signal peaks. Makes weak signals POP RIGHT UP out of the noise! This is really helpful for digital modes too.

Likewise, the notch filter is excellent. Although not automatic, it is quick and easy to adjust so as to notch out an interfering hetrodyne. If more than one interfering signal exists, then the broader "Aux. Notch" can be used.

In practice during normal use, the Lowpass mode is selected. Selectivity and Frequency can then be adjusted to give a really pleasant and readable sound on all modes - AM, FM, CW and SSB. I've even used it on 2m FM to boost quiet voices :).

Even among today's plethora of digital signal processing systems, the Autek QF-1A still holds its own and can even outperform some DSP systems due to its analog nature - i.e. no digital artifacts and virtually no delay.

Add one of these to your station along with a good quality speaker and you'll really notice a positive difference!
N4UE Rating: 2017-12-20
You won't believe this! Time Owned: more than 12 months.
Long post! sorry.
I have a huge boatanchor collection (22 Drakes for example). I've read about the Autek filters and have been accumulating them for years.
I also have a bunch of Timewave, Datong and every other brand of NON-DSP filter made.

Here's something that I still find mind boggling......
I recently rebuilt one of my operating positions. I call it the Icom position. I now have a 756PRO I bought new in Tokyo the week it was announced. Next to it I have my new 7610 and my 7300. Also some Icom VHF/UHF radios.

So, I did a little 6M experiment last weekend.
I have a quiet location. Antenna is a M2 6M7JHV at 105' fed with 7/8" Hardline.
I also have one of my all time favorites over on the Drake position, my beloved TR-6/RV-6 combo. The Drake has new JFETs and has been carefully aligned.
(that review is on this site as well).

So, I found a VERY weak CW beacon, well down into the noise. I then switched between the TR-6, the 756PRO, the 7300 and the 7610. All Icoms were on USB with only Preamp 1 on. I do not have a CW filter for the TR-6. Also, no attempt was made on the Icoms to enhance reception. There is NOT much to tweak on the Drake!

To my astonishment, switching between all 4 (using a quality coax switch) made little difference in readability of this signal. Non of the Icoms could show it on the 'scope or waterfall.
OK, I have a QF-1A connected to the TR-6. Once I switched it on, I was astounded by the overall increase in quality of the received signal. It sounded like a local! Switching the filter off, bypasses it and the S/N ratio was as before.

Bottom line? I have a bunch of these filters packed away and may have to dig them out for the newer gear.
These are on eBay all the time for a reasonable price.

Please note again, this was a CW audio filter test only.
Just kinda shocked me.....

ron
N4UE
WQ6X Rating: 2017-09-03
Autek QF-1A a Nice Surprise Time Owned: 6 to 12 months.
Months ago I relieved someone of a QF-1A for $7.50 - not being a contester he didn't know what to do with it.
Mine comes with the A.C. plug and I much PREFER it that way for portable indoor operations.
Splitting the Left/Right Channel audio lines on the FT-1000mp, I route the Sub-RX audio
through the QF-1A, using the radio's built-in DSP for the Main RX.
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 almost as good (as long as there is no AGC pumping).
W5BBB Rating: 2017-05-15
A great addition to FRG-7 Time Owned: 0 to 3 months.
I just got comfortable with my newly acquired Yaesu FRG-7 when I came across a QF-1A at a local hamfest. $3?? Was he serious? SOLD! I downloaded the instruction manual and the first day, I was all sorts of confused. On the second day, I "broke the code" and now it's a keeper. It adds clarity, selectivity and listening comfort above-and-beyond the capabilities of my already great vintage receiver. Yes, even in 2017, it's a superb addition to the Frog-7 and (most likely) any vintage rig. You can keep your DSP, I'll take a QF-1A.
RSHIRE22 Rating: 2013-11-19
aok Time Owned: more than 12 months.
I bought this filter for ssb/cw but was disappointed because I soon discovered I couldn't stop fiddling with it. Seems like anyway I adjusted it I was never satisfied with the sound. CW worked best using Peak and adjusting notch and frequency until the signal peaks. On ssb the best setting is Lowpass with notch and frequency from 7-9 o'clock. Lots of artifacts and other noises along with the signal you want.

Eventually I discovered my favorite use of the filter - hi fi shortwave listening. I set Aux Notch to 9; Peak; Notch to 10:30; Frequency to 5. Does wonders listening to music on shortwave and AM - rich warm sound with high intelligibility.
NH6RF Rating: 2013-10-10
Can't go wrong! Time Owned: 0 to 3 months.
Bought this after reading the reviews for use with an FT-840. The only filtering the FT-840 offers is an IF shift. Took about 30 minutes of playing with the controls to determine preliminary settings. The previous owner had left marks on the face where his preferred settings were. I removed them and started from scratch. The filter I bought off the auction site had been modified for two inputs. Nice touch. I now have an IC-735 on one input and the FT-840 on the other. I usually listen to some 40 meter nets early in the morning. With this filter the audio receive quality has been greatly improved, especially using the "peak" setting. Signals that have been barely readable are now louder and clearer. I can easily check the difference buy simply turning it off as it is equipped with bypass when off. Remarkable difference. Not a must have for your shack, but a nice to have for sure, especially if your rig doesn't have any built in filtering. I was using a Timewave DSP 9+ audio filter but no longer. This older filter works far better at least on SSB and CW. Don't know about the digital modes, yet.
K4JPN Rating: 2012-07-28
Great Time Owned: more than 12 months.
I bought one years ago 2nd hand, and used it with my HW-8. The HW-8 filter was wide a barn door, but with the QF-1A I could really separate the signals. After many years of use the power switch/bypass switch failed. Replaced it and had some strange feedback. I simply rerouted the audio leads to the bypass portion of the switch and I was back in business.

----------------------
Earlier 5-star review posted by K4JPN on 2011-11-19

I picked up one at a hamfest 25 years ago, used it primarly with my HW-8. Anyone who has owned a HW-8 knows the filters leave a lot to be desired. The Autek QF-1A with the HW-8 made a great combination. I could pull signals through the QRM and noise with ease. After many years of use the power/bypass switch failed, so I rewired in a new switch and that is the only problem I have ever had with it.
KG4FET Rating: 2012-05-09
Worth Every Penny!!!! Time Owned: 6 to 12 months.
This the best 25.00 I have spent on my ham station EVER! I bought mine a year ago and came to me with a bad cable, fixed that and could not believe the difference. Used behind my Triton IV into the 262 power supply's speaker this wonderful little filter helps what is already a fantastic receiver to be that much better. Having been without it for a couple of days due to a bad contact in the switch (which can be taken apart and repaired) I am that much more appreciative of it.

There is a learning curve with the unit though. READ THE MANUAL, play with the settings, don't give up on it. Once you learn the unit there will be almost nothing it won't pull out of the noise. This is now an indispensable part of my station. Mine is used on AM, SSB, and CW. AC only operation here is not a problem

Keep in mind the notch is variable. It will not be perfect for every tone coming in on one setting as in an auto notch. For rigs with AF dsp's , no filtering or limited filtering this is the best AND cheapest way to add filtering. Worked great with my 747, and now the Triton IV.
73
DE KG4FET Sandor