Manager - NA4M
Manager Notes

Reviews For: Almost All Digital Electronics Precision Frequency Reference

Category: Tools & Test Equipment for the amateur radio work bench

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : Almost All Digital Electronics Precision Frequency Reference
Reviews: 2MSRP: 49.95
Assembled and calibrated against my Rubidium frequency

to better than 0.1 parts per million (1Hz at 10MHz)

with long term accuracy of 1 part per million (1Hz at 1MHz)
Product is not in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
NASSAU Rating: 2014-12-02
Simple and cost-effective Time Owned: 0 to 3 months.
I purchased this RF standard in order to align a kit QRP transceiver that I am building. I was looking for something portable and simple and this appeared to fit the bill.

This is not exactly a kit itself, as it is supplied already assembled, but not affixed to its hard plastic case. The reason is that this RF standard needs a DC (or AC) power supply and AADE's Neil Hecht encourages reuse of an old wall wart, to be soldered to the PCB and then closing the case. There is a 9V (PP3) battery connector already attached, but this is part of the calibration/testing process at AADE.

I desoldered the battery connector, reused a 12V DC 1.5A wall wart I had lying around, drilled the case for an access hole, soldered it up and closed the box.

Initial testing of the TCXO at 10MHz was favourable on my oscilloscope, but I do not have a specific frequency counter to see greater decimal place accuracy.

My next test was to listen to the beat frequency between this RF standard and my Elecraft KX3. The KX3 is an all-digital SDR rig and have confidence that its DDS VFO is top notch.

I placed the RF standard close to the rig's antenna BNC connector, but did not connect the rig to the AADE box. While in SSB mode, I used USB to dial towards the 10MHz VFO setting, listening to the difference in frequencies that became audible in the rig headphones. I managed
10,000,070 Hz before the tone was too low for my hearing. Similarly, with LSB I dialled up the VFO and the beat note fell below my hearing at 9,999,930 Hz. On the basis of this holistic approach, the AADE RF standard fairs pretty well at around 7ppm error. But I am sure the symmetry of this range (140Hz) about 10MHz would suggest the true frequency output of the RF standard is actually a lot closer to 10Mhz.

The instruction sheet advises that with suitable rubidium standards, 0.1ppm can be achieved. While Neil mentions he has no long-term experience of the RF standard itself to attest to the stability, he mentions he uses the same TCXO in his line of frequency counters where there are examples that have drifted only 7ppm in 6 years between calibrations.
There IS a multi-turn trimmer pot on the PCB board to tweak calibration, but I have not tried this since I do not have anything more accurate as a reference. That's the whole point I bought this product to begin with!

For the price of $55 (around £35 UK), excluding postage and packing, this little box is a great value, hence the '5' score. The low price point is apparent in the paper facia of the box, rather than something made of sheet plastic. The PCB is perhaps closer to home-etched than production run quality (no solder mask, etc). But none of that affects the results.

Get one and you'll be happy with the simplicity and effectiveness of this useful ham radio tool.
VA3MW Rating: 2013-11-29
It just works Time Owned: 0 to 3 months.
I have been struggling to find a frequency standard that I can move around so I can ensure a few things are calibrated. Like my IFR-1200.

I ordered one and it arrived last night. Still skeptical, I ran the wwv calibration routine on my Flex (a pretty cool feature) as a reference and then inserted this to check it at 10, 20 and 60Mhz.

All I can say is that at 10Mhz, it was off < 1Hz (I don't have resolution less than that). At 60Mhz, it was off less than 3 Hz.

The details are on his web page, but pretty handy to have around.

In the end, it turns out my IFR was out by about 6Hz, but it had been decades since it was last fully calibrated.

Quick service with a confirmation on delivery time when I ordered it.

I love things that 'just work'