That is the huge advantage of the now available new technologies: You have a Chinese Menu (literally) of so many approaches. Regrettably old what's his name has screwed the deal on the cheap part.
But the options are many even after paying for the tariff. Thus, today I offer some of those options. The esp32 devices come in a variety of form factors. The device below I discovered in my junk box still NIB and likely bought early on and discarded because it looked like a clunky Arduino Uno R3. But hey it works.
WEMOS esp32 with a 128x160 ST7735 TFT
The kind of neat news is that Lauren Sanchez's boyfriend is selling a 3 pack of this board for $17. This board has WiFi and Blue Tooth.
While it too is clunky, the wiring is done using pin headers inserted into the onboard sockets, which makes for rapid prototyping and if used with the Heathkit "HW" series monobanders, space is not an issue. A bonus of this particular esp32 is the rapid prototyping aspect using the pin headers.
Still another option is a simple Arduino with a 16X2 LCD. Yesterday I dug out the Ten Tec Triton II and yet again was amazed how this 50-year-old radio was updated using the external VFO box complete with keypad up down tuning and the ability to work +10, - 10 kHz splits for DX pileups. The frequency was rock solid and no squinting trying to read 10Hz changes
I have been cycling through some of my boat anchor treasures and am chagrined that as hams we actually put up with drifting analog VFO's. We also paid a lot of money for these crappy radios. Yet for a few bucks we can turn these derelict hunks of junk into silk purses with rock solid tuning and color displays.
Recently I spotted a Triton II on eBay from jaguardog which was priced buy it now for about $190. Knowing what I know can be done with a remote VFO box -- probably only about $40 high, which coincidentally is about the cost of the remote box. Just think -- a Nano, Keypad, Si5351 and a 16X2 LCD. The case was hand made by me using thin hobby aluminum and PC Board which were in the junk box.
Today we presented a couple of options and these are only a few of the many. But you can't be an appliance operator with a very small knowledge base and no digital experience and have expectations of pulling this off.
That time wasted in the parks yelling CQ POTA or on mountain tops yelling CQ SOTA does not substitute for learned skills. So, start small, learn and in time you will eventually experience the thrill of conceiving a project like this remote VFO and having it work!
Them that know can make it go.
73's
Pete N6QW