IC-R8500 10.7 MHz IF output: useable for panorama adaptor?
Bart Wessel
I already did a google search, but couldn't find much. Also the online
copy of the manual doesn't help.
The signal level would probably suffice, but I am asking because
someone claimed that there is only output on the IF-out jack when in
wide-FM mode, because the output was only intended for use with the
TV/StereoFM adaptor. I'm not sure how, and if, this would limit the
use of a panorama adaptor.
One of the articles did mentioned a 9V DC riding on the IF-out to
power the TV/FM adaptor, so I'd have to block that with a capacitor.
Anyone care to comment?
Come to think of it: does anyone know the IF-out's bandwith?
Bart.
There may be a 'NOSPAM.' in front of my E-mail address.
It is there to fool machines, not people.
Please remove it when you reply.
Mark Holden
I'm not familiar with your radio, but the IF output is normally after
the selectivity filters.
If so, it will probably be useless for a panadapter.
The filters are there to keep the signals you'd want to see on your
panadapter from stepping on the signal you're tuned to.
One of my first experiments was to feed the output of the 2nd IF on my
Harris RF-550 into a spectrum analyzer. It was a waste of time.
The place to tap off of is after the first mixer, but before the first
filter. I've been advised it makes sense to use a high impedance buffer
amplifier to avoid degrading the signal.
Dino AL7LZ
will interface directly with the Icom 7100 that I have and I'm going to guess
and say the 8500 since it will work with the TV-R7100 TV/FM adapter I think.
There is in fact a DC voltage at that port; it's used to power the adapter so
be careful.
The two adapters I know of are the AOR SDU5500 and the Avcom PS45 Models A
(CRT) and B (LCD). Grove Enterprises sells both. The Avcom's have a DC block
built into them so you don't have to provide your own; don't know about the AOR
unit though.
I'm planning on getting the Avcom to use with my R7100 and TenTec RX340 as you
can order a second IF input (and BNC cable connections on the back if you
like).
Both units have been reviewed in Monitoring Times and Bob Grove is pretty
knowlegeable about them.
GL -- Dino KLØS/4
Bart Wessel
For anyone interested: the adaptor I am refering to is not a dedicated
Icom device. Have a look at
http://www.helmut-singer.de/stock/1011866273.html
(Helmut Singer is not the only one selleing these).
Eric F. Richards
> Would the IF-output of the R8500 be useable for a panorama adaptor?
Yes. The output is wide enough to allow a 6 MHz TV signal to go
through. I have used the output this way with a real spectrum
analyzer to see if it could be done. Some notes:
o The IF is "mirrored" so signals to the "left" of the current
signal are higher in frequency than those to the "right."
o The AGC somewhat kills the effect -- tuning in a strong
station will decrease the sensitivity of the radio and your
panadapter, so weak adjacent signals will be lost.
o WARNING! WARNING! There is a 9VDC supply on the 10.7 MHz
output. Some panadapters/spectrum analyzers can tolerate
a DC component on their RF-in, others cannot. CHECK TO
MAKE SURE.
...one I may be wrong on...
o I seem to recall that the "mirroring" above wasn't consistent.
Depending on what frequency band you were in, the scope acted
"normal" or "mirrored" as described above.
Eric
--
Eric F. Richards, efr...@dim.com
"This book reads like a headache on paper."
www.cnn.com/2001/CAREER/readingup/08/14/getting.things.done/index.html
Eric F. Richards
Bart,
This is a followup to your request about info regarding a panadaptor
on the ICOM 8500.
I bought one of these and it *finally* arrived this week.
Time from order to arrival: 5 weeks.
Summary: Would I do it again? NO.
Details: The shipping via Bundespost and U. S. Postal Service
bounced it around an awful lot, and I had to open up the unit to
tighten screws (mounting ones, not the transformers. :-)) and
reconnect the anode cap to the CRT.
I should note that the unit is not designed for rough handling
during shipping. The unit is held in its case by two spring-
loaded "quick release" knobs on the front. Because the springs
are old, the back of the unit bounces around in its case.
Once visually checked out and put back together I connected it
to 24VDC and it promptly blew a fuse. Replacing the fuse got
it to work.
I feed it from the IF out on my '8500 through a blocking cap
(there's a DC component on the IF out). The problem is that
even at its most sensitive setting, the scope isn't sensitive
enough to use with the ICOM.
There's a front-panel sensitivity setting but I keep it at
maximum to make it even a little usable. Probably there's
a coarse sensitivity setting inside but I haven't found it.
Fortunately the supplied manual is in well-written English.
The one thing that is nice about it is that it is an analog
device and sweeps like an analog device -- probably 10-20
sweeps a second.
Two things would make me recommend this: Better packing to
protect it, and better sensitivity. I may be able to fix
the latter, and if so, will post a followup.
Eric
--
Eric F. Richards, efr...@dim.com
"Nature abhors a vacuum tube." -- J. R. Pierce, Bell Labs, c. 1940
Eric F. Richards
> I feed it from the IF out on my '8500 through a blocking cap
> (there's a DC component on the IF out). The problem is that
> even at its most sensitive setting, the scope isn't sensitive
> enough to use with the ICOM.
>
> There's a front-panel sensitivity setting but I keep it at
> maximum to make it even a little usable. Probably there's
> a coarse sensitivity setting inside but I haven't found it.
I should note that it is possible that somewhere, internally,
the panadaptor is set for a linear vertical scale instead of
logarithmic, which would cause exactly the same problems I
see with it.
--
Eric F. Richards, efr...@dim.com
"The most likely way for the world to be destroyed, most
experts agree, is by accident. That's where we come in;
we're computer professionals. We cause accidents."
- Nathaniel S. Borenstein
Bob_Parnass_AJ9S
SM-220 panadaptor with ICOM receivers -- not enough
signal to produce good vertical deflection.
I solved the problem by inserting an Ameco FET shortwave preamp
between the radio's 10.7 MHz IF output and the panadaptor's vertical
input (coupled through a DC blocking capacitor).
Make sure you tune the preamp to 10.7 MHz.
On Fri, 22 Mar 2002 08:38:40 -0600, Eric F. Richards wrote:
> This is a followup to your request about info regarding a panadaptor on
> the ICOM 8500......
> I feed it from the IF out on my '8500 through a blocking cap (there's a
> DC component on the IF out). The problem is that even at its most
> sensitive setting, the scope isn't sensitive enough to use with the
> ICOM.
--
=========================================================================
Bob Parnass, AJ9S par...@megsinet.net http://members.core.com/~parnass
Linux user
Bart Wessel
Eric, thanks for sharing.
I wrote:
>> (Helmut Singer is not the only one selleing these).
If at any time in the future I make such a statement again, contact me
before buying. I did not buy from Helmut Singer, see below for more
reasons why. I found another supplier, have a look at
http://www.rainer-foertig.de/index.html
Eric wrote:
>I bought one of these and it *finally* arrived this week.
>Time from order to arrival: 5 weeks.
>
>Summary: Would I do it again? NO.
I *am* sorry to hear that.
I got mine from Rainer. I was fortunate enough to be able to arrange
for it to be picked up and it arrived in very good condition. Not a
fair comparison because mine never had to go through several different
postal services on an international trip.
I've only just received it, but it worked straight out of the box.
[shipping details]
Apparently Singer doesn't value his customers enough to care for
decent packaging, or maybe your unit was particularly badly handled.
I have heard other stories about Helmut Singer keeping the best stuff
for people visiting his store and sending the less ones by mail.
I do not know about this from personal experience though.
If anyone cares to comment on this, please do.
Also I do not know how Rainer's packaging would be. As I said, my unit
was picked up at his shop.
>I feed it from the IF out on my '8500 through a blocking cap
>(there's a DC component on the IF out). The problem is that
>even at its most sensitive setting, the scope isn't sensitive
>enough to use with the ICOM.
Agreed. I do get a visible signal, often enough to reach full scale.
But at times I would also want a bit extra, and I guess an amplifier
would definately do some good. I've mainly used it on VHF and UHF.
If yours doesn't ever reach full scale, maybe the blocking cap you use
is to small? Or the unit neeeds a tune up. Full details are in the
manual. The manual is very clearly written and includes setup and
calibration procedures. Also a full parts list and a full schematic
are in there. Mine is in German, but that is no problem to me.
>Two things would make me recommend this:
> Better packing to protect it,
Good advice for anyone who is going to order one - be it form Helmut
or Rainer.
> and better sensitivity. I may be able to fix
>the latter, and if so, will post a followup.
Please do. I know I am interested!
I'd like to add: ask for a manual in a language you can read.
Apparently there are English and German ones available.
I find the unit a nice extra, but not exactly a must-have.Still the
price (remember: no shipping costs for me) was right and I do not
regret the purchase. A typical case of 'your mileage may vary'!
Best wishes,
Eric F. Richards
> I had the same problem when using a modified Kenwood
> SM-220 panadaptor with ICOM receivers -- not enough
> signal to produce good vertical deflection.
>
> I solved the problem by inserting an Ameco FET shortwave preamp
> between the radio's 10.7 MHz IF output and the panadaptor's vertical
> input (coupled through a DC blocking capacitor).
>
> Make sure you tune the preamp to 10.7 MHz.
>
I was thinking of doing more-or-less the same thing. At home
somewhere, lost in the move, is a Ten-Tec T-Kit broadband preamp,
essentially one MMIC with support parts, which would be perfect
for the job. But I am hoping there is a coarse setting internal
to the Telefunken panadapter.
Eric
> On Fri, 22 Mar 2002 08:38:40 -0600, Eric F. Richards wrote:
>
> > This is a followup to your request about info regarding a panadaptor on
> > the ICOM 8500......
>
> > I feed it from the IF out on my '8500 through a blocking cap (there's a
> > DC component on the IF out). The problem is that even at its most
> > sensitive setting, the scope isn't sensitive enough to use with the
> > ICOM.
--
Eric F. Richards
Bart Wessel <nospam...@home.nl> wrote:
> Hi Eric and group,
>
> Eric, thanks for sharing.
>
> I wrote:
> >> (Helmut Singer is not the only one selleing these).
> If at any time in the future I make such a statement again, contact me
> before buying. I did not buy from Helmut Singer, see below for more
> reasons why. I found another supplier, have a look at
> http://www.rainer-foertig.de/index.html
>
> Eric wrote:
> >I bought one of these and it *finally* arrived this week.
> >Time from order to arrival: 5 weeks.
> >
> >Summary: Would I do it again? NO.
> I *am* sorry to hear that.
>
> I got mine from Rainer. I was fortunate enough to be able to arrange
> for it to be picked up and it arrived in very good condition. Not a
> fair comparison because mine never had to go through several different
> postal services on an international trip.
>
> I've only just received it, but it worked straight out of the box.
>
> [shipping details]
> Apparently Singer doesn't value his customers enough to care for
> decent packaging, or maybe your unit was particularly badly handled.
Well, by and large the packing was good, but not tailored to the
nature of the beast -- for example, there was an inner cardboard
wrap around the unit, then probably 6 in. (15 cm) of styrofoam
peanuts, then the main box. The problem is that the panadaptor
is held in its case by only two screws, so more support inside
that cardboard wrap would have been helpful.
> I have heard other stories about Helmut Singer keeping the best stuff
> for people visiting his store and sending the less ones by mail.
> I do not know about this from personal experience though.
> If anyone cares to comment on this, please do.
That would make sense -- the unit I received was in considerably
worse physical shape than the photo on the web site -- the top
protection plate was pushed down a centimetre or so, which must
have taken effort!
> Also I do not know how Rainer's packaging would be. As I said, my unit
> was picked up at his shop.
>
> >I feed it from the IF out on my '8500 through a blocking cap
> >(there's a DC component on the IF out). The problem is that
> >even at its most sensitive setting, the scope isn't sensitive
> >enough to use with the ICOM.
> Agreed. I do get a visible signal, often enough to reach full scale.
> But at times I would also want a bit extra, and I guess an amplifier
> would definately do some good. I've mainly used it on VHF and UHF.
>
> If yours doesn't ever reach full scale, maybe the blocking cap you use
> is to small? Or the unit neeeds a tune up. Full details are in the
> manual. The manual is very clearly written and includes setup and
> calibration procedures. Also a full parts list and a full schematic
> are in there. Mine is in German, but that is no problem to me.
Mine is in English, but I don't think it has a full schematic -- just
some of the subsystems and a block diagram.
I think it is working fine as the calibration line appears just as it
should at full scale. But the idea was to see the weak ones in the
spectrum and it doesn't help much there.
> >Two things would make me recommend this:
> > Better packing to protect it,
> Good advice for anyone who is going to order one - be it form Helmut
> or Rainer.
>
> > and better sensitivity. I may be able to fix
> >the latter, and if so, will post a followup.
> Please do. I know I am interested!
>
> I'd like to add: ask for a manual in a language you can read.
> Apparently there are English and German ones available.
I got the English one and it is also well written, with only
an occasional syntax error. Something I would like to be able
to claim for my own writing! :-)
> I find the unit a nice extra, but not exactly a must-have.Still the
> price (remember: no shipping costs for me) was right and I do not
> regret the purchase. A typical case of 'your mileage may vary'!
>
> Best wishes,
> Bart.
>
Definitely a YMMV item, yes. The price was right after converting
to dollars, and even after gasping at the shipping cost.
Thanks much for the reply! And don't worry about any problems I
had buying them -- the choice to do so was mine, no one else's.
Eric
--
Eric F. Richards
efr...@dim.com
"The weird part is that I can feel productive even when I'm doomed."
- Dilbert
Eric F. Richards
This is my followup on this thread with regard to adding an amplifier
between the ICOM and the panadapter.
Bart Wessel <nospam...@home.nl> wrote:
> Hi Eric and group,
>
> Eric, thanks for sharing.
[...]
> >I feed it from the IF out on my '8500 through a blocking cap
> >(there's a DC component on the IF out). The problem is that
> >even at its most sensitive setting, the scope isn't sensitive
> >enough to use with the ICOM.
> Agreed. I do get a visible signal, often enough to reach full scale.
> But at times I would also want a bit extra, and I guess an amplifier
> would definately do some good. I've mainly used it on VHF and UHF.
>
> If yours doesn't ever reach full scale, maybe the blocking cap you use
> is to small? Or the unit neeeds a tune up. Full details are in the
> manual. The manual is very clearly written and includes setup and
> calibration procedures. Also a full parts list and a full schematic
> are in there. Mine is in German, but that is no problem to me.
>
[...]
> > and better sensitivity. I may be able to fix
> >the latter, and if so, will post a followup.
> Please do. I know I am interested!
>
Well, getting a preamp was harder than it sounds. Bob Parnass used an
Ameco preamp but that was awfully expensive. I couldn't find my
Ten-Tec preamp kit that I bought years ago, so I ordered another.
It's still on backorder, and the folks in Tenessee are probably going
through what I just went through -- you see, the T-T amp is one MMIC,
the MSA-0104, and it is no longer available.
So, I got the Ramsey preamp kit instead. It was reasonably cheap and
small, but more work than putting one MMIC, two caps and a choke on
one board. :-) I added a blocking cap to keep the DC component off
the input and a choke to supply the DC to the appropriate place. The
kit's ads say 12 volts minimum, but the assembly guide says 8 volts.
Anyway, it sits in a 1 inch by 1 inch by 2 inch box with two BNC
connectors. The ICOM supplies the DC power.
The end result? Quite helpful -- not as much as I wanted, but about
what I expected. Above 30 MHz, the Telefunken panadapter is very
useful and can help you find that elusive new frequency. Below 30
MHz, the 10.7 MHz IF is just too narrowly filtered to make it a "must
have" accessory.
> I find the unit a nice extra, but not exactly a must-have.Still the
> price (remember: no shipping costs for me) was right and I do not
> regret the purchase. A typical case of 'your mileage may vary'!
So, readdressing the question, would I do it again? Not for HF use.
The specialized scopes of the HF receivers do a better job. However,
the scope on the late, great ICOM 9000 is useless above 30 MHz, and
the panadapter shines there. So it was a worthy effort after all.
However, I'll continue looking for either of the two spectrum analyzer
plugins for the HP 800-series mainframes I have... :-) The Holy Grail
search continues! :-)