[TenTec] Cheap rig

[Geoffrey S. Mendelson]

On Mon, Apr 21, 2008 at 06:49:50PM -1000, Ken Brown wrote:
> And I still don't think deleting CW capability would make it sell better.

It depends upon the price difference. Since the rig I imagined had a
digital synthesizer as its signal source, it would have to be "pulled" to
transmit. In plain English if you used a 455kHz IF (as cheap components
are available for it), you would have to have it shift the synthesizer
frequency 455kHz when you keyed the transmitter.

Digital synthesizers spend a finite time changing frequencies. The better
the chip (more expensive), the more repeatable and shorter that time is.

For SSB one can easily use a chip with a relatively long "startup" time,
many FM radios used them for years. All one needs is a bit of firmware,
or an RC network to mute the audio until the delay is passed. Since an SSB
transmitter won't transmit with muted audio, it solves a simple problem
cheaply.

CW is much more difficult. The timing needed is both finite and repeatable.
If you delay the start of transmission too long, you risk "swallowing" the
first dit/dah. If you don't delay it enough, you risk off frequency transmission,
and other keying "noises". 

Too much delay also moves you from QSK to VOX (delayed return) keying, to
a transmit switch. QSK may be too confusing, but a manual transmit switch
would be too much to ask. 

So adding CW mode adds complexity and requires a more expensive synthesizer
chip which adds cost.

The second issue is IF filtering. Hams who got novice licenses in the 1960's
are used to copying one signal in a pile up. Hams who are used to the Internet,
cell phones, VoIP, etc and never learned to copy CW for a license, can't do it.
It just sounds like a mess of noise and they get easily frustrated and confused.

So IMHO, in order to attract new hams with no CW background, we need to have
an IF or AF filter to reduce the passband. This again adds cost and complexity.

I'm not even going to speak to the issue of a keyer, except that I think it
would be a great addition to a CW option, but the total cost of such an
option, with a narrow (say 1kHz) IF filter, key click suppression, and
a keyer would add around $100 to the price of the rig. Even if it only
added $50, that would be 1/4 of my price target.

I know someone was speaking tongue-in-cheek when they suggested no mic jack,
but it makes some sense to me. Having a mic jack adds cost, complexity and 
another mechanical point of failure. Having a wired in mic adds cost because
you have to supply the mic. What I am not sure about, being outside of the
U.S., is the value of preventing CB microphones (beep, echo, etc) of finding
their way onto these rigs. At one time you could pick them up at a flea market
for a couple of dollars (often with the CB rig too). I don't know about now.

Again, my point is to make the best SSB rig for as little money as possible,
without adding any features that increase cost. Not only do I not want to make
someone think they are paying for something they don't need (or want), I don't
want to flood the bands with bad sounding CW signals because I cheaped out
and added a poor quality Morse code option.

Geoff.

-- 
Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM