Speaking of radios that might NEVER exist....
 

What ever happened to the SUPER M.W. radio that some guy here on the group
was building? (Pete?)

--
Jim

Jim Hackett wrote:
What ever happened to the SUPER M.W. radio that some guy here on the group
was building? (Pete?)

--
Jim


Hi Jim,
The radio design is complete................I am just waiting for our
software prople to write the control code for the spectrum analyzer
functions, synthesizer control functions, etc. I have built 3 prototypes
that use a ten turn pot to tune the VCO, and they work quite well. The
latest version uses a GaAsFET MMIC as the loopstick amplifier.
I do have one issue............the TDA1572 seems to act as a good
antenna for picking up 31M band signals, so I need to work out a
shielding scheme. I am not sure if the power supply lines or the chip
itself are picking up the signals, but it shouldn't be to hard to work out.
We have a couple of multi-million dollar projects we are working on
right now, to the software people have put the radio on the back burner
for now.
It could be a blessing in disguise.............I am working on plans for
a Fraction N synthesizer, and I may try a different approach to the
design, using a quad JFET mixer.In its current configuration, the
sensitivity is on a par with the AOR7030, which is ok for MW.
The RF amplifier is a pretty strong device; it will put out 50mW of
linear power, with a 1dB compression point of +18.5dBm. It should be
fairly bulletproof in a congested signal area.
I was going to use an Agilent MG82563, and I still might, but right now,
I am using an RF Micro Devices RF2044, with a source follower ahead of
it to match the impedance of the loopstick to this device.

Pete

Any idea on price/availability?


"Pete KE9OA" wrote in message
...
Jim Hackett wrote:
What ever happened to the SUPER M.W. radio that some guy here on the
group
was building? (Pete?)

--
Jim


Hi Jim,
The radio design is complete................I am just waiting for our
software prople to write the control code for the spectrum analyzer
functions, synthesizer control functions, etc. I have built 3 prototypes
that use a ten turn pot to tune the VCO, and they work quite well. The
latest version uses a GaAsFET MMIC as the loopstick amplifier.
I do have one issue............the TDA1572 seems to act as a good
antenna for picking up 31M band signals, so I need to work out a
shielding scheme. I am not sure if the power supply lines or the chip
itself are picking up the signals, but it shouldn't be to hard to work
out.
We have a couple of multi-million dollar projects we are working on
right now, to the software people have put the radio on the back burner
for now.
It could be a blessing in disguise.............I am working on plans for
a Fraction N synthesizer, and I may try a different approach to the
design, using a quad JFET mixer.In its current configuration, the
sensitivity is on a par with the AOR7030, which is ok for MW.
The RF amplifier is a pretty strong device; it will put out 50mW of
linear power, with a 1dB compression point of +18.5dBm. It should be
fairly bulletproof in a congested signal area.
I was going to use an Agilent MG82563, and I still might, but right now,
I am using an RF Micro Devices RF2044, with a source follower ahead of
it to match the impedance of the loopstick to this device.

Pete

Jim Hackett wrote:
Any idea on price/availability?

It should be in the 300 dollar range..............availability is
unknown. Right now, the only ones in existance are the prototypes that I
have built up. As soon as the HF bands open up, I should be able to
solve that shielding problem with the I.F. subsystem.
I am not sure where you are located, but if you ever get into the
Chicago area, give me a shout. I will be able to demonstrate one of the
prototypes for you.

Pete

LOL I'm on the "other" side of the country. In the hands of "The
Terminator"



"Pete KE9OA" wrote in message
...
Jim Hackett wrote:
Any idea on price/availability?

It should be in the 300 dollar range..............availability is
unknown. Right now, the only ones in existance are the prototypes that I
have built up. As soon as the HF bands open up, I should be able to
solve that shielding problem with the I.F. subsystem.
I am not sure where you are located, but if you ever get into the
Chicago area, give me a shout. I will be able to demonstrate one of the
prototypes for you.

Pete

Pete KE9OA wrote:

Jim Hackett wrote:
Any idea on price/availability?

It should be in the 300 dollar range..............availability is
unknown. Right now, the only ones in existance are the prototypes
that I have built up. As soon as the HF bands open up, I should be
able to solve that shielding problem with the I.F. subsystem. I am
not sure where you are located, but if you ever get into the Chicago
area, give me a shout. I will be able to demonstrate one of the
prototypes for you.

Pete

does your design compare to the "winradio" for $999.00 US?

Pete KE9OA wrote:

Jim Hackett wrote:
Any idea on price/availability?

It should be in the 300 dollar range..............availability is
unknown. Right now, the only ones in existance are the prototypes that I
have built up. As soon as the HF bands open up, I should be able to
solve that shielding problem with the I.F. subsystem.
I am not sure where you are located, but if you ever get into the
Chicago area, give me a shout. I will be able to demonstrate one of the
prototypes for you.

Pete

Any word on when/if the sync' detector might be available as an outboard
option? I would love to try it on a car radio.


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Hi folks,
In the order received, this radio will be quite a bit better than the
Winradio. Mr. Starman, the Sync detector will be available as an
outboard accessory.............I just am not sure when. I did release
the detector design to one of the US radio manufacturers (don't ask me
who!), so it should show up in the next version of that manufacturer's
radio.
Oh, that image problem..............I was receiving Radio Bejing's
9790kHz frequency. I solved the problem in two ways. First of all, I
shielded the TDA1572 by covering it with a strip of copper tape,
soldering both ends of the tape to the ground plane.
The image occured because of this reason............with a 10.7MHz 1st
I.F. and a 455kHz 2nd I.F. I decided to use a 2nd LO injection frequency
of 10.245MHz. Since this is a low-side injection scheme, the radio can
respond to the 10.7MHz upper sideband response of the mixer (the desired
one) and the 9.790MHz lower sideband response (the image). Once I
identified this mechanism, I was able to solve the problem by inserting
a low-pass filter between the JFET source follower and the wideband
MMIC. With my Boonton Model 103D RF Generator set at a 1V output level,
radiating directly into the loopstick antenna, the response is down
-70dB. Problem solved.
Now, if I could only get those softward people at
work...................this unit will also have RS-232 control, and we
will have some sort of Windows based GUI program to control the radio.
For you Linux folks, we will be releasing the protocols, so you will be
able to write your control code.
Overall, I am happy with the design, and I think that all of you will
like it. I talked to the boss about releasing a barebones, portable
version of this radio, with only a preselector control, volume control,
and tuning control, but he didn't go for it. Too bad............it would
have captured the under 150 dollar market.

Pete

I knew there was something I forgot to mention.............the loopstick
amplifier now has a low-pass filter with a 2.5MHz cutoff that follows
the JFET source follower, and a bandpass filter that follows the 20dB
GaAsFET MMIC (this was always there), so when we do market the active
antenna as a stand-alone unit, it should be fairly bulletproof.
After installing the low-pass filter after the JFET, I did notice that
the system gain had increased, so I would surmise that the MMIC was
being driven into gain compression by the multitude of signals in the RF
spectrum. This device has a frequency response from DC to 6GHz.
Also noted before I added the low-pass filter were some spurious
responses from either the FM or TV band. I will characterize this
amplifier chain with a spectrum analyzer later this week, just to make
sure that I don't get any more spurious responses.
Time to go to sleep for a couple of hours...............back to work at
10:00 this morning for another round!

Pete

Do you have a picture somewhere of the prototype?

jcj


Pete KE9OA wrote in message ...
Jim Hackett wrote:
What ever happened to the SUPER M.W. radio that some guy here on the group
was building? (Pete?)

--
Jim


Hi Jim,
The radio design is complete................I am just waiting for our
software prople to write the control code for the spectrum analyzer
functions, synthesizer control functions, etc. I have built 3 prototypes
that use a ten turn pot to tune the VCO, and they work quite well. The
latest version uses a GaAsFET MMIC as the loopstick amplifier.
I do have one issue............the TDA1572 seems to act as a good
antenna for picking up 31M band signals, so I need to work out a
shielding scheme. I am not sure if the power supply lines or the chip
itself are picking up the signals, but it shouldn't be to hard to work out.
We have a couple of multi-million dollar projects we are working on
right now, to the software people have put the radio on the back burner
for now.
It could be a blessing in disguise.............I am working on plans for
a Fraction N synthesizer, and I may try a different approach to the
design, using a quad JFET mixer.In its current configuration, the
sensitivity is on a par with the AOR7030, which is ok for MW.
The RF amplifier is a pretty strong device; it will put out 50mW of
linear power, with a 1dB compression point of +18.5dBm. It should be
fairly bulletproof in a congested signal area.
I was going to use an Agilent MG82563, and I still might, but right now,
I am using an RF Micro Devices RF2044, with a source follower ahead of
it to match the impedance of the loopstick to this device.

Pete