For those trying to solder those TSSOP and TQFP AD
chips into a circuit I found this site on the net

http://aprilog.com/perl/main.pl

They sell adaptors to solder the chip onto to plug
into standard dip sockets.

There are other types of breadboard circuit boards
for these chips as well. Search on google for
"TSSOP breadboard" or "TQFP breadboard".

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.

Anybody have any 'war stories' about using these DDS
chips in a rig as a vfo?

I think the problem with these is going to be placing the bypass caps close
enough to the chip, and also getting good low-impedance RF ground paths.
For just a little more money, you can buy an entire DDS board with all parts
from NJQRP.

Let us know how you make out.

Joe
W3JDR


"Ken Scharf" wrote in message
...
For those trying to solder those TSSOP and TQFP AD
chips into a circuit I found this site on the net

http://aprilog.com/perl/main.pl

They sell adaptors to solder the chip onto to plug
into standard dip sockets.

There are other types of breadboard circuit boards
for these chips as well. Search on google for
"TSSOP breadboard" or "TQFP breadboard".

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.

Anybody have any 'war stories' about using these DDS
chips in a rig as a vfo?

In article ,
says...
For those trying to solder those TSSOP and TQFP AD
chips into a circuit I found this site on the net

http://aprilog.com/perl/main.pl

They sell adaptors to solder the chip onto to plug
into standard dip sockets.

There are other types of breadboard circuit boards
for these chips as well. Search on google for
"TSSOP breadboard" or "TQFP breadboard".

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.

Anybody have any 'war stories' about using these DDS
chips in a rig as a vfo?


The Aprilog adaptors do work. I've used them on both AD9852/AD9854
chips and ATmega128 chips. Drawbacks a 1) they aren't exactly free;
and 2) Aprilog can be a little quirky to deal with at times, although
they've always come through for me in the end. (I think it's a one- or
two-man shop that sometimes gets overwhelmed with business.) They will
sometimes cut you a good deal on slightly-nonstandard stock.

They are certainly preferable to hand-soldering. I'd say give 'em a try
with the 9900-series DDS parts and report back to let us know your
results.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

"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.

...

xpyttl wrote:

Hi

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.

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?

Thanks,
Paolo IK1ZYW

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

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

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