#1185 HF VFO 20kHz to 220MHz

Episode 1185
WARNING: +12dbm output power square wave

[Hammerjockeyrepair]

the reason the front says transceiver is because it goes with a few other components to make a complete mini ham station, They sell the transmitter and receivers that match this cute lil box

[germanjohn]

In typical fashion, he made a video without exploring the functions of the unit. Had he done so, he would have found that pressing the IF button longer he could cycle through 3 different setting, 455khz IF, 10.7Mhz IF and no IF, straight generator mode. The nice thing with this unit is that the amplitude is pretty stable over the wide range not like other junk on the market and thus a step attenuator can be used to make a pretty good signal generator for sensitivity measurements. We bought 10 of them for a school project from different sources, every single one of them was maximal +- 1-5Hz off at 10Mhz. Pretty darn good for a device like this.

[PAJPR]

This project is just a copy of the guy that has designed it, and put it on youtube one year ago, see below.
Same display layout etc.

10kHz to 225MHz VFO / RF Generator with Si5351 and Arduino Nano, with Intermediate Frequency (IF) offset
(+ or -), RX/TX Selector for QRP Transceivers, Band Presets and Bargraph S-Meter. See the schematics for
wiring and README.txt for details. By J. CesarSound - ver 2.0 - Feb/2021.

[andymouse]

Nice little build and now you tidied it up even better...cheers.

[PlonsNard]

A small correction: it is not Arduino based. Both (many of) Arduino's and this device are AVR-based. Atmel was taken over by Microchip several years ago.

[johnwest]

So it's designed to be used as the front-panel of a wide-coverage transceiver with a 455 kHz IF, but for some reason it didn't sell, so they put the front-panels in boxes and are trying to sell them as VFO's. But you can't program it to match your IF and you have to make sure that the odd order harmonics are suppressed, at least on xmit. Oh, and they want close to a hundred bucks for them. Good luck with that.

[cbradiohamfan]

✅😎kool vids …👍
Hello would this be good to use on the ubitx v3 to controll the frequencies ?? 🎉🎉

[francisdevasia]

How to change IF frequency to another one ?

[RideGasGas]

Output port is mis-labeled. Frequencies in kelvin hertz (KHz) to mega hertz (MHz). Should be kilo hertz (kHz) to mega hertz (MHz).

[MrRW]

well for data modes you need a signal carrier and then in a second unit you can do the frequency shifting stuff...russia studiec every time 5-6 times the propagation of experimental carriers bevor the applied the MFSK XX stuff ....you can create your personal data mode on HF

[willthecat]

Thanks for the interesting video. This thing, with shipping, is the better part of 100 USD, on Prime. For 20 bucks, OK; but, for 20 or 30 dollars more, you can get a complete Chinese wide band SDR receiver. Maybe stuff like this wouldn't see the light of day, beyond China, if it wasn't reviewed, and implicitly recommended on YouTube.

[jspencerg]

PSA suggestion: Always show insertion of attenuator when testing unknown sources(though this battery powered thingy unlikely high power).

[keithdensmore]

I have one of these. Is is possible to program a different IF shift? (I need 2.920 MHZ).

[byronwatkins]

For those with quadrature encoders, swap either the two phase A wires or the two phase B wires -- don't swap A wires for B wires.

[tonyfremont]

Seems like there would be software options for the direction and IF settings. Surely it can tune in finer steps than 5kc too.

[fromgermany]

I know some guys are not really used to metric, so I’m already happy about not being confronted with an imperial frequency measurement. But there is big difference between mHz and MHz, as m and M are case sensitive in metric of about 10^9.
milli and Mega is not exactly the same 😂

[NavinF]

Here’s a silly question from someone with very little experience with RF stuff: Why do expensive HF radios exist? Given a stable clock, can’t any 300mhz microcontroller output a square wave at ~10mhz which can be amplified with a couple of cheap MOSFETs and filtered with a 2 pole low-pass filter to remove the harmonics and get a band limited signal you can broadcast?

[chrisharper]

Isn't the thing kind of worthless given all the harmonics? I was also wondering about jitter.

[bumohamedubualooy]

can u make a video about ad 9851 dds i cant get a steady sine wave even in under 5 Mhz from it. tnx in advance

[paulcohen]

Is it Okay to call a square wave generator "VFO" for a receiver?