NEWER UPDATEThese are pieces of shit. Basically, the circuit for measuring frequency (not their goddam crystal checker circuit) doesn't work at all. I would not piss on the makers of these piles of fecal matter if they were on fire. As far as I am concerned, they can all die and go to hell with a hard-on.
That is my final word on the matter.
I need to do a retraction of sorts here. While I am still somewhat agitated by the lack of support by the seller of these items, I would like to go on record as saying, once revived, it appears these might actually be quite useful. Let me bring you up to date.
It seems -- after all my poking and prodding -- the second unit "woke up" and began working. Once that was in place it was a simple matter to debug the first unit -- which was truly moribund. Seeking and getting advice from Chuck Adams, K7QO, over on the QRO Tech Yahoo group, I swapped out out the PIC chip, trading the good board's chip for the bad board's chip. The fact that the good board performed correctly no matter which PIC chip was aboard revealed that BOTH chips were fine and dandy. Next, I timidly put the good board's chip into the bad board -- and yet it still slept with the fishes. Remembering back to my earlier debugging effort where checking the crystal operation on pins 15 and 16 revealed a nice clean 20 MHz trace (well, 19.997 MHz, actually) on the good board and bupkis on the other, I thought to swap out the crystal on the bad board.
Of course, these little guys are the "low-rider" HC-49/U cases and wicking out the one on the good board and soldering it into the bad board would have been dicey at best. So, reaching into my cavernous junk box, I grabbed a 16 MHz crystal (that I checked out in my PacifiCon crystal checker AND the good board's crystal checker first) and "welded" that in place.
Viola! The bad board awakened and began perking along nicely.
So I am forced to conclude it was a bad crystal all along. It cycled through the menu, saved offsets (more below) and, of course, the results of checked crystals were off by about 4 MHz. But all I had to do was get some ("Get some! Get some! Get some, baby!") new 20 MHz crystals and I'd be set.
I pulled the trigger on a local auction (to hell waiting a fortnight for some guy in a warehouse in China get around to sending me them), and was the proud owner of what I thought was six or seven 20 MHz jobbies. Sadly or happily, the quantity count turned out to be FIFTY!
Remember the 19.997 MHz comment above? Well the good board was off by 3 KHz so it seems as though a the 19.997 MHz may be causing the error. The price was right on the batch that I got, so I can wade through all fifty, find one or two of them dead on, and swap out the old crystals for the new accurate ones.
Another plus of the design is deriving the offset if this is going to be used as a frequency display for a radio. You merely go into menu mode, measure the IF of the radio in question and then press "ADD" or "SUB" to obtain the appropriate offset and call it a day. The VFO frequency will then be ADDed or SUBed to the stored offset and Bob's your uncle. I am guessing that you can also set the IF by using a signal generator. How the hell will the counter know?
Add to the fact that the plastic case looks kind of nice -- much better than saving a few bucks and putting the display in some kludged-together pile of soldered PCB.
So, looks like the rain clouds are parting and the sun is coming out after all.
O.K., so there's only one in the picture. But I bought two of these units off eBay from a Chinese dealer in the mysterious Orient and it turns out that the only goddam thing that was mysterious about BOTH units was that they did not work when I assembled them.
What a waste of time and money. Oh, they do offer a money back guarantee but one has to go through the effort (and cost) of mailing the crap back to those pirates.
And, yes, I assembled them both carefully. And, yes, because the first one did not work, I MEASURED and TESTED each part I put onto the board of the second one. And, no, neither one worked.
But to be fair, the second one worked for a few minutes and then crapped out. And, when it did work, it blinked and gagged out some mysterious prompts via the display. Pushing the button only brought on more weird behavior and mysterious prompts before it finally faded into oblivion. Of course, I had given the dealer a positive rating when the packages arrived. And, of course. I sent the dealer a message telling him that his piles of Chinese crap sucked. (I was more polite than that. Next message will not be.)
But to my original cause for aggravation over these units: the single piece of toilet paper that the Chinglish instructions were written on. You know, the ones with the microscopic printing and faded, unintelligible diagrams. (I don't expect a damn Heathkit manual, but they could have invested a little more effort in the instructions, fer crissakes!) And as for operating instructions once these are up and running? Non-existent. Not a whisper of a hint of a breath of a word about how to measure frequencies or crystals or set the offsets.
..which is what these are worth.