xpyttl wrote:
"Ken Scharf" wrote in message
...


Now that I see it might be possible I'm going to try
and make use of those 9954 and 9851 chips I got as
samples. The 9932 looks interresting too, with it's
low power. I also want to get a sample of the 9834,
now THAT's a low power chip, perfect for QRP.


Well, don't be too excited just yet. Even though the chips themselves might
be on a diet, they need a high frequency oscillator to get a decent waveform
out. Those little oscillator cans start to draw amazing amounts of current
when the frequency creeps up. Heck, the ocsillator on my 9850 DDS draws
more current by itself than an entire K1.

FAR circuits has a DDS board that is a little more complete than the NJQRP
dauhtercard, if that's what you are looking for, but the quality of that
board has been pretty bad. I know they are trying to improve it, but I
can't say I've been impressed with the results. On the other hand, they do
have prototyping boards that are quite nice. I picked up a few at a hamfest
this past fall that are pretty decent for the TSSOP DDS parts. And they are
a LOT cheaper than the individual adapters. However, their online catalog
doesn't have the selection they had at the hamfest, so maybe a call to them
would be in order.

The NJQRP daughtercard really does reduce the pain of all this, but both the
daughtercard and the FAR circuits DDS card are for the 9850, which is
getting a little stale. Sounds like you want to play with some newer stuff.

Also take a peek at some of the TI stuff. They have synthesizers and
"transmitter" chips that are very reasonably priced. Although they are
intended for very high frequencies, Steve Weber has made them work down into
more reasonable frequencies, and prescalers are only a couple of bucks.

I haven't found a link where you can buy the NJQRP daughtercard, he
seems to have the artwork for downloading but that won't do me much
good. The 9851 seems to be pin compatible with the 9850 and will go
higher in frequency using a lower frequency (lower powered) oscillator.
The 9954 family is much smaller in size than the 9850 family (closer
pin spacing) so dead bug on these would be about impossible, the
circuit board is a must. I found some other bread board adaptors but
the problem is that there can't be any traces UNDER the 9954 because
there is a ground pad there. I can carefully cut away the unused
portions of one of these (http://www.devrs.com/store/) which is a
universal breadboard, drill a hole through the middle and solder
a wire to the ground pad. BTW I thought I'd have a problem interfacing
to the 9954 because it runs on 1.8v (how to hook it to a 5v 8051?), but
the io part of the chip is powered by it's own pin that can run at 3.3v
and then it will tolerate 5.5v max on the digital inputs. Problem
solved!

BTW many here seem to like PICs, but I'm just more familiar with the
8051 series. IF you don't need external ram or io on the 8031 and
and use an external EPROM you still have 16 io lines available, it's
then a three chip solution (8031, 74x573, 27x512). There are simulators
C compilers and assemblers for the 8051 that run on Linux (don't know
about the pics). I DO wish that people that post articles using these
micros on the web or in qst would make the SOURCE CODE available!!!
Not doing so is like NOT making the SCHEMATIC available for a homebrew
article!!!

I do mean KD1JV. However, I don't think Steve ever wrote anything up. If I
recall, he used the TRF4900 which is a "transmitter" - basically a DDS with
an amplifier. The 4400 looked a little more interesting to me, same thing,
lower frequency. I've been meaning to do something similar for a while now.
I had assumed that you needed to operate these parts somewhere near their
spec frequency, 900 MHz for the 4900, 450 for the 4400. Steve went right
down to 6 meters for his first whack and had no problems.

What is interesting about these is that they are reasonably priced, and the
frequency steps are small enough that you are in the neighborhood of a Hz or
two after dividing them down to HF, reasonable for a CW rig. They are also
easily obtained.

TI also has a series of synthesizer chips, the 2050 and 2052 that seems to
be a bit more flexible, but maybe more complicated. All these parts are
under five bucks quantity one.

I have to admit, after getting over my shyness over asking AD for samples,
the AD parts look a lot more appealing. But I have a few of these TI chips,
and I finally got a prototyping board that will work with them, now if I can
just get the time to play with them...

...

"PaoloC" wrote in message
...
xpyttl wrote:

Do you have any reference to Weber's project? I would love to have a
look at that circuit!

BTW, do you mean SteveN Weber, KD1JV?

I do mean KD1JV. However, I don't think Steve ever wrote anything up. If I
recall, he used the TRF4900 which is a "transmitter" - basically a DDS with
an amplifier. The 4400 looked a little more interesting to me, same thing,
lower frequency. I've been meaning to do something similar for a while now.
I had assumed that you needed to operate these parts somewhere near their
spec frequency, 900 MHz for the 4900, 450 for the 4400. Steve went right
down to 6 meters for his first whack and had no problems.

What is interesting about these is that they are reasonably priced, and the
frequency steps are small enough that you are in the neighborhood of a Hz or
two after dividing them down to HF, reasonable for a CW rig. They are also
easily obtained.

TI also has a series of synthesizer chips, the 2050 and 2052 that seems to
be a bit more flexible, but maybe more complicated. All these parts are
under five bucks quantity one.

I have to admit, after getting over my shyness over asking AD for samples,
the AD parts look a lot more appealing. But I have a few of these TI chips,
and I finally got a prototyping board that will work with them, now if I can
just get the time to play with them...

...

"PaoloC" wrote in message
...
xpyttl wrote:

Do you have any reference to Weber's project? I would love to have a
look at that circuit!

BTW, do you mean SteveN Weber, KD1JV?

I do mean KD1JV. However, I don't think Steve ever wrote anything up. If
I
recall, he used the TRF4900 which is a "transmitter" - basically a DDS
with
an amplifier.
Steve went right
down to 6 meters for his first whack and had no problems.

If they can be taken down to HF also, it would be very easy to make a CW tx
for 17 - 10 meters with such DDS-PLL chips. Right now that is not so
interesting, but by the time we approach the next solar peak (2008+?), there
may be many more such chips available also.



--
Sverre Holm, LA3ZA
---------------------------------
www.qsl.net/la3za

I do mean KD1JV. However, I don't think Steve ever wrote anything up. If
I
recall, he used the TRF4900 which is a "transmitter" - basically a DDS
with
an amplifier.
Steve went right
down to 6 meters for his first whack and had no problems.

If they can be taken down to HF also, it would be very easy to make a CW tx
for 17 - 10 meters with such DDS-PLL chips. Right now that is not so
interesting, but by the time we approach the next solar peak (2008+?), there
may be many more such chips available also.



--
Sverre Holm, LA3ZA
---------------------------------
www.qsl.net/la3za

Sverre Holm wrote:


down to 6 meters for his first whack and had no problems.


If they can be taken down to HF also, it would be very easy to make a CW tx
for 17 - 10 meters with such DDS-PLL chips. Right now that is not so
interesting, but by the time we approach the next solar peak (2008+?), there
may be many more such chips available also.

Yep, and in smaller packages too! :-) Those mentioned by xpyttl are in
TSSOP packages if I recall correctly: way too small to hand-solder!

Sometimes I am "frustrated" by the huge amount of useful ICs for HAM
homebrewing shipped in ultra-space-saving packages. :-(

Ciao,
Paolo IK1ZYW

Sverre Holm wrote:


down to 6 meters for his first whack and had no problems.


If they can be taken down to HF also, it would be very easy to make a CW tx
for 17 - 10 meters with such DDS-PLL chips. Right now that is not so
interesting, but by the time we approach the next solar peak (2008+?), there
may be many more such chips available also.

Yep, and in smaller packages too! :-) Those mentioned by xpyttl are in
TSSOP packages if I recall correctly: way too small to hand-solder!

Sometimes I am "frustrated" by the huge amount of useful ICs for HAM
homebrewing shipped in ultra-space-saving packages. :-(

Ciao,
Paolo IK1ZYW

"PaoloC" wrote in message
...
Sverre Holm wrote:


down to 6 meters for his first whack and had no problems.


If they can be taken down to HF also, it would be very easy to make a CW
tx
for 17 - 10 meters with such DDS-PLL chips. Right now that is not so
interesting, but by the time we approach the next solar peak (2008+?),
there
may be many more such chips available also.

Yep, and in smaller packages too! :-) Those mentioned by xpyttl are in
TSSOP packages if I recall correctly: way too small to hand-solder!

Sometimes I am "frustrated" by the huge amount of useful ICs for HAM
homebrewing shipped in ultra-space-saving packages. :-(

TSSOP is easy to solder using the 'drag soldering' technique. I use a
special Metcal system with a hoof tip, but it can be done with ordinary
soldering equipment. Plenty of liquid flux is the secret to success.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller

"PaoloC" wrote in message
...
Sverre Holm wrote:


down to 6 meters for his first whack and had no problems.


If they can be taken down to HF also, it would be very easy to make a CW
tx
for 17 - 10 meters with such DDS-PLL chips. Right now that is not so
interesting, but by the time we approach the next solar peak (2008+?),
there
may be many more such chips available also.

Yep, and in smaller packages too! :-) Those mentioned by xpyttl are in
TSSOP packages if I recall correctly: way too small to hand-solder!

Sometimes I am "frustrated" by the huge amount of useful ICs for HAM
homebrewing shipped in ultra-space-saving packages. :-(

TSSOP is easy to solder using the 'drag soldering' technique. I use a
special Metcal system with a hoof tip, but it can be done with ordinary
soldering equipment. Plenty of liquid flux is the secret to success.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller

I do mean KD1JV. However, I don't think Steve ever wrote anything up.

Here's his account using the TRF4400:

http://www.kkn.net/archives/html/QRP.../msg01621.html


--
Sverre Holm, LA3ZA
---------------------------------
www.qsl.net/la3za