K7QO issues a QRP kit challenge

k7qo-challenge.txt

Gang,

I am teaching a live CW course using my CD. Two weeks into the course.

About to get to the sending part. So, looking for several ways to get 27
students on the same page. Has to be cheap, they only paid $10 for the
course which goes into the club treasury and I don't charge a dime, as
I don't want to lose any one due to placing a hardship on their budget.

In 2002, Dave Benson K1SWL, came out with the Rock Mite. What?
8,000 units sold since then? And no telling how many built home brew.
It was the deal of the century. IMHO. Original price was $25.
Easy and fun to build. I have a couple.

Used a PIC 12F508 uP. The hex file is on the ARRL Handbook CD for
2004 and maybe other years. I used a couple of the keyers in my own
homebrew rigs.

Now the Rock Mite is $50. This puts it on the steep slope as to how
much students will spend in addition to the cost of the key or paddle.
I will find out this Wednesday during the class. The power is not at
a level where I think a beginning QRP operator is going to have fun
or even much success. I would think it will try their patience level
significantly.

OK. Found a kit for $24.10 from China on ebay. Sent off for it. 6 
Days from
the return key to the package in the mailbox. Faster than a first class
letter across the USA. :-) BTW. $24 for an experiment I do not consider
excessive. IMHO.

Opened the package. The PCB is first class. Very clean and nice plated
through holes. I spent three days building the thing. Not a rig for 
beginners.
Lousy docs, both in English and printing. No instructions. Just the 
parts layout,
the schematic in fine printing and some printing missing or printed 
badly and
the parts list. No turn counts on the toroids and the transformer 
(bi-filar). Spent
a lot of time doing emails and googling the Universe.

Got it assembled and photographed in all its gory details.

<http://www.k7qo.net/super-rockmite.html>

Gotta give me credit for patience and stamina in doing the job in detailed
format. :o)

In the search on the Internet, I found a number of references to individuals
not getting theirs to work. No surprise there. First thing I found was 
a 7806
in place of the 7805. Most people are going to think that it's OK and 
put it in
and go on. Bad idea. The STC12C4052AD uP, the Chinese version of the
Intel 8051 old processor, is rated 5.5V max for Vcc. Zap. Gone. So this
killed a lot of the kits if that was the part supplied.

The kit started up just fine. But it is worthless. It is not a Rock 
Mite. It has
a serial RS232 interface, which the Chinese think is the way to go and use
a terminal program to send CW. The uP is used to generate the side tone.

I guess the designer is not a CW operator and has never touched a real
Rock Mite. There is no Iambic mode, either A or B. :-( It acts like a
Cootie type keying, i.e. you get a dit and you get a dah with each contact
with left and right paddle, but no continuous string of dits or dahs if 
paddle
is left depressed/closed. Bummer. Real bummer. A real crying shame.

Spec sheet says automatic detection of straight key, like Dave had in his
code, but that is a mistake. No auto detection for straight key, or I would
be able to use it.

So, I have to call this a brick. Just sits there and does nothing.
Draws 84mA with the RS232 chip in it, 72mA if I take the chip out.
RS232 is just about dead in this century.

I'm stealing the RF section for a test. The final PA costs $0.20 from the
Chinese and rated to 12.5W. Rig does output 5W with no problem on 40m.

Don't waste your money or time on one of these critters. I've already
done that for you.

------------------------

OK, there are two other options and I placed orders for same. Report
coming later when I get them. Cost now at $55 and $47 for the two
options.

-----------------------

Here is a design challenge. Club project.

o $30 kit
o 20m
o 4W CW xcvr
o builtin keyer
o 14.040-14.060 tuning range
o decent receiver sensitivity

Here is something that I see, and this is just me. The large active clubs
are supporting their activities and one big gathering every year by
having kits. I support this and I buy a lot of kits to show my support.
The lab is full of them on shelves and in drawers. Most are built and not
in the original boxes.

What is missing is a club doing one kit with low profit margin for the
entry level QRPer and beginning hams to get them started in the hobby.
I have one 15 year old student in the current class. We need more.
I'm not to ask about their budget. I just have to assume that it is not
large and go from there. They have too much going on in this busy
Universe.

I do not know if the goal is reachable. But I'd like to try and get there.

---------------------------

OK. I'm back to the lab. Found the following, which I am excited about.

<http://blog.radioartisan.com/arduino-cw-keyer/>

I got some of the uPs for $1.77 each. So I have to see how easy the
software is going to be to configure. It has a lot of features that I like
in a keyer. I'm still using a CMOS III for rigs that do not have an 
internal
keyer.

If this works, then the QT-20 is scrap and a start over is planned using
this keyer.

-------------------------------------

Film at 11.

chuck, k7qo