EMRFD Message Archive 2777

Message Date From Subject
2777 2009-03-24 12:28:00 Chris Trask The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the Sco
I've been working on this noise blanker project for almost four weeks
now, and I finally have a working system. All I need to complete it is
about 50 feet of RG-58A/U cable.

I prototyped two different approaches. The first one would have
required about 3,600 meters of cable for the time delay equalization. Not
good. This one needs just 15-20 meters. Not perfect, but certainly better.

I felt that the design was good enough at this point that others may be
interested in duplicating it, so I wrote up what I have at this point and
put it on my web page at:

http://www.home.earthlink.net/~christrask/Paper020.htnl


Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2778 2009-03-24 13:19:15 Stephen Wandling Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
There is a typo in the link, it should read:

http://www.home.earthlink.net/~christrask/Paper020.html



Chris Trask wrote:
> I've been working on this noise blanker project for almost four weeks
> now, and I finally have a working system. All I need to complete it is
> about 50 feet of RG-58A/U cable.
>
> I prototyped two different approaches. The first one would have
> required about 3,600 meters of cable for the time delay equalization. Not
> good. This one needs just 15-20 meters. Not perfect, but certainly better.
>
> I felt that the design was good enough at this point that others may be
> interested in duplicating it, so I wrote up what I have at this point and
> put it on my web page at:
>
> http://www.home.earthlink.net/~christrask/Paper020.htnl
>
>
> Chris
>
> ,----------------------. High Performance Mixers and
> / What's all this \ Amplifiers for RF Communications
> / extinct stuff, anyhow? /
> \ _______,--------------' Chris Trask / N7ZWY
> _
2779 2009-03-24 13:48:54 Don Hackler Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
2780 2009-03-24 14:02:55 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> I've been working on this noise blanker project for almost four weeks
> now, and I finally have a working system. All I need to complete it is
> about 50 feet of RG-58A/U cable.
>
> I prototyped two different approaches. The first one would have
> required about 3,600 meters of cable for the time delay equalization. Not
> good. This one needs just 15-20 meters. Not perfect, but certainly
better.
>
> I felt that the design was good enough at this point that others may
be
> interested in duplicating it, so I wrote up what I have at this point and
> put it on my web page at:
>
> http://www.home.earthlink.net/~christrask/Paper020.htnl
>

I made a typo error on the URL in this posting. It should be:

http://www.home.earthlink.net/~christrask/Paper020.html


Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2781 2009-03-24 16:03:18 leon Heller Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
----- Original Message -----
2782 2009-03-24 16:18:49 Dan Rae Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Chris Trask wrote:
> my web page at:
>
> http://www.home.earthlink.net/~christrask/Paper020.htnl
>
>

That's html then not nl for those who are puzzled...
dr
2783 2009-03-24 17:11:27 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Yep, just sent out a bunch of corrections about that.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2784 2009-03-24 19:53:12 Chris Howard Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
That is really a good writeup.

How did you go about researching the older circuits? Is that something that
you
did a library search for? That really added a lot for me. I enjoyed
reading some
of the history of the concept.

Chris
w0ep



----- Original Message -----
2785 2009-03-24 20:36:31 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> That is really a good writeup.
>
> How did you go about researching the older circuits? Is that something
that
> you did a library search for? That really added a lot for me. I enjoyed
> reading some of the history of the concept.
>

I did a literature search using INSPEC, which is a high-powered British
search engine that goes back to 1889 or so. It's available bound from then
until the 80's, and it's available electronically back to 1969. Looking
through the earlier bound volumes is very time-consuming. And I used IEEE
Xplore, which I have access to here at home by way of my IEEE membership.

Also did a patent search on USPTO. In all cases, I look up each
reference that is cited, and then the ones I found there, etc., etc. until I
run out of references to look up. It seems like a lot of time is taken, but
it beats reinventing the wheel.

I get some papers by way of friends in Australia and elsewhere. We have
an informal literature gathering community that goes back and forth. I
managed to get copies of Vackar's oscillator paper by way of a Hungarian TV
engineer many years ago in exchange for a bunch of stuff that he was unable
to find.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2787 2009-03-25 00:43:01 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> > http://www.home.earthlink.net/~christrask/Paper020.htnl
>
> Should be:
>
> http://www.home.earthlink.net/~christrask/Paper020.html
>

Yeah, sent out a correction earlier this afternoon.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2788 2009-03-25 10:52:59 Dave Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
2789 2009-03-25 13:34:06 Dave Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
2790 2009-03-25 14:21:38 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
----- Original Message -----
2791 2009-03-25 18:38:18 Gary Johnson Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
I really enjoyed reading your scholarly writeup on the noise blanker. Good work. This delay line stuff is very interesting... Makes me want to start experimenting!

Data Delay Devices still makes some small, passive (LC) delays with good RF performance and they have 50 ohm models. Have a look here: <http://www.datadelay.com/asp/passive.asp> Not sure where you would buy these though.

Toko has some delay lines. Pretty challenging wading thru their online catalog. Digikey turns up a couple of part numbers, but no stock.

Keep us informed...

-Gary, WB9JPS
2792 2009-03-25 19:03:31 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> Data Delay Devices still makes some small, passive (LC) delays with good
RF
> performance and they have 50 ohm models. Have a look here:
> <http://www.datadelay.com/asp/passive.asp> Not sure where you would buy
these
> though.
>

Nice, but the 3dB cutoff frequency is about 1/tD, where tD is the total
delay of the device. For 100nSec delay, the cutoff would be about 10MHz.
I'm learning slowly that the cable delay line may be the only suitable
approach for this. I can get a 50' RG-58/U cable with BNC connectors from
All Electronics for just $8.95. It might not be premium cable, but at least
it will provide the finishing touch for this. They also have shorter
lengths, and I may end up with one of each.

>
> Toko has some delay lines. Pretty challenging wading thru their online
catalog.
> Digikey turns up a couple of part numbers, but no stock.
>

Yes, saw those many days ago. No stock = no sale.

I'm still looking at patents and I have some other references, but I
think that the 1/tD rule will apply to all of these passive L/C delay lines,
even the helical and distributed parameter coaxial types. I noticed that
with PSpice earlier. But, I will track down any possibility.


Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2793 2009-03-25 20:08:54 ehydra Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Is there a reliable source of TOKO parts for counts of ten to 200?
Sometimes I consider using one but I think buying them is the first step
to a headache.

What about second-source, maybe of India or China?

I'm in Germany. As always, I prefer cheap (ok, say affordable) for me :-)


regards -
Henry


--
www.ehydra.dyndns.info



Gary Johnson schrieb:
> I really enjoyed reading your scholarly writeup on the noise blanker. Good work. This delay line stuff is very interesting... Makes me want to start experimenting!
>
> Data Delay Devices still makes some small, passive (LC) delays with good RF performance and they have 50 ohm models. Have a look here: <http://www.datadelay.com/asp/passive.asp> Not sure where you would buy these though.
>
> Toko has some delay lines. Pretty challenging wading thru their online catalog. Digikey turns up a couple of part numbers, but no stock.
>
> Keep us informed...
>
2794 2009-03-25 20:09:09 ehydra Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Chris Trask schrieb:
> It is, but for the moment it's the one practical alternative that I have
> available. The helical delay lines are a definite possibility, but I either
> need to find an affordable commercial one or just do it myself with a
> ferrite rod and some wire.
>

A single ferrite rod will not work! Just because all stages will be
magnetically coupled together. You must stagger several units.
I can send you such a delay-line if postage is compensated.

Look for a old Tektronix scope with delayed time-base. There is such a
delay line circuit design.

Have you ever considered the PAL delay line? It is approx. 64us delay.


regards -
Henry

--
www.ehydra.dyndns.info
2795 2009-03-25 20:52:18 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> A single ferrite rod will not work! Just because all stages will be
> magnetically coupled together. You must stagger several units.
> I can send you such a delay-line if postage is compensated.
>

I have yet to convince myself that the delay line approach is suitable
due to the 1/tD frequency cutoff problem.

>
> Look for a old Tektronix scope with delayed time-base. There is such a
> delay line circuit design.
>
> Have you ever considered the PAL delay line? It is approx. 64us delay.
>

The 64uSec would be way in excess of what's needed for this. This
blanker will need a delay line of 50-150nSec, and the passive L/C types will
have a cutoff frequency that's well below the spectrum I would like this to
work with. The RG-58/U will at least let it work most of the HF spectrum
without significant losses.

One solution I've been considering is having a narrow-band time delay
section, which will require a separate one for each band of interest. Or
perhaps I can devise a wider bandwidth version and come up with a suitable
method of alignment. Even so, that might be preferrable to using 50-75' of
cable.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2796 2009-03-26 07:14:39 Gary Johnson Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Chris,

Here is what DDD says
2797 2009-03-26 08:13:51 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> Here is what DDD says on the datasheet for the model 1515: "The rise
> time (TR) of the line is 10% of TD, and the 3dB bandwidth is given
> by 3.5 / TD." So in their table, they show 35 MHz BW for the 100 ns
> model. Maybe there's hope for delay lines in the longer term. But for
> now it's hard to beat the cheap and available roll of coax, I'd agree.
>

Thank you for passing that along. Now I understand the language of these things a little better. The last one I had looked at was the 1517. Seems that the cutoff frequency is directly related to tR/tD.

Here's another manufacturer:

http://www.cornucopiaplastics.com/ec2/products/l-c_delay_lines/index.htm

I'll have to see if I can obtain a couple as samples from these places to see if they will work. In the meantime, I'm looking at some passive circuits, but nothing worth mentioning as of yet.



Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2798 2009-03-26 10:21:59 WB6TPU Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Chris-

What kind of delay (i.e. phase) stability do you need in the delay line? Will there be issues over temperature?

Many years ago I interviewed at a place that was building IFM (instantaneous frequency measurement) receivers for the military. The unit had a delay line discriminator that "instananeously" but out a DC level proportional to the frequency of the strongest signal in the passband. That level was measured and the frequency of a synthesized receiver was then tuned to that frequency. I think the whole thing was used for "spook" Sigint work. They showed me the delay line assembly which was about 20 feet or so of semi-rigid cable wound on a bobbin. They had temperature related issues (phase jumps) that they ultimately cured by temp cycling the delay line assembly multiple times to relieve mechanical stresses.

Using RG58 type cable I would imagine the stress problem would probablt be a non-issue, but their still may be issues of delay variation over temperature. Whether they are severe enough to cause concern is the question. I'd kind of guess the sort of delay variations you might see in the cable will be lost in the noise...

-Ray WB6TPU
2799 2009-03-26 10:41:42 ehydra Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Floeth in Germany and Dallas Semi are other sources.


Noise Blanker circuits are already included in some radio ICs.


regards -
Henry


Chris Trask schrieb:
>> Here is what DDD says on the datasheet for the model 1515: "The rise
>> time (TR) of the line is 10% of TD, and the 3dB bandwidth is given
>> by 3.5 / TD." So in their table, they show 35 MHz BW for the 100 ns
>> model. Maybe there's hope for delay lines in the longer term. But for
>> now it's hard to beat the cheap and available roll of coax, I'd agree.
>>
>
> Thank you for passing that along. Now I understand the language of these things a little better. The last one I had looked at was the 1517. Seems that the cutoff frequency is directly related to tR/tD.
>
> Here's another manufacturer:
>
> http://www.cornucopiaplastics.com/ec2/products/l-c_delay_lines/index.htm
>
> I'll have to see if I can obtain a couple as samples from these places to see if they will work. In the meantime, I'm looking at some passive circuits, but nothing worth mentioning as of yet.
>


--
www.ehydra.dyndns.info
2800 2009-03-26 10:42:39 ehydra Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Soemthing very similar is a FM delay-line demodulator. There was one in
Revox receiver. Good for linearity.

regards -
Henry


WB6TPU schrieb:
> Chris-
>
> What kind of delay (i.e. phase) stability do you need in the delay line? Will there be issues over temperature?
>
> Many years ago I interviewed at a place that was building IFM (instantaneous frequency measurement) receivers for the military. The unit had a delay line discriminator that "instananeously" but out a DC level proportional to the frequency of the strongest signal in the passband. That level was measured and the frequency of a synthesized receiver was then tuned to that frequency. I think the whole thing was used for "spook" Sigint work. They showed me the delay line assembly which was about 20 feet or so of semi-rigid cable wound on a bobbin. They had temperature related issues (phase jumps) that they ultimately cured by temp cycling the delay line assembly multiple times to relieve mechanical stresses.
>
> Using RG58 type cable I would imagine the stress problem would probablt be a non-issue, but their still may be issues of delay variation over temperature. Whether they are severe enough to cause concern is the question. I'd kind of guess the sort of delay variations you might see in the cable will be lost in the noise...
>
> -Ray WB6TPU
>

--
www.ehydra.dyndns.info
2801 2009-03-26 10:53:01 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> Here is what DDD says on the datasheet for the model 1515: "The rise time
(TR) of
> the line is 10% of TD, and the 3dB bandwidth is given by 3.5 / TD." So in
their
> table, they show 35 MHz BW for the 100 ns model. Maybe there's hope for
delay lines
> in the longer term. But for now it's hard to beat the cheap and available
roll of
> coax, I'd agree.
>

I got off the phone with their sales department a few minutes ago. The
1515-100A costs $11.63 in 10pc quantity and they have a $75 minumum order.
By the piece that's cheaper than a 50' RG-58C/U cable from Pasternack, which
will run you about $55 with shipping. The All Electronics cable is just
$8.95, but I doubt that the cable itself is of very good quality. It is,
however, an affordable and available alternative.

I was not able to find a second supplier that had anywhere near the DDD
performance, and I stopped looking at the passive delay networks. With the
cable or the commercial delay line available, it's much easier to go that
route and there's no alingment needed. That makes this a solder-and-play
design.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2802 2009-03-26 11:04:05 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
> What kind of delay (i.e. phase) stability do you need in the delay line?
Will
> there be issues over temperature?
>
> Many years ago I interviewed at a place that was building IFM
(instantaneous
> frequency measurement) receivers for the military. The unit had a delay
line
> discriminator that "instananeously" but out a DC level proportional to the
> frequency of the strongest signal in the passband. That level was measured
and
> the frequency of a synthesized receiver was then tuned to that frequency.
I
> think the whole thing was used for "spook" Sigint work. They showed me the
> delay line assembly which was about 20 feet or so of semi-rigid cable
wound on
> a bobbin. They had temperature related issues (phase jumps) that they
ultimately
> cured by temp cycling the delay line assembly multiple times to relieve
mechanical
> stresses.
>
> Using RG58 type cable I would imagine the stress problem would probablt be
a
> non-issue, but their still may be issues of delay variation over
temperature.
> Whether they are severe enough to cause concern is the question. I'd kind
of guess
> the sort of delay variations you might see in the cable will be lost in
the noise...
>

I'm quite certain that there will be spme temperature dependence, but
most of the variation will be in the noise receiver and detector. I
measured the time delay difference for the two paths and I'm comfortable
that the difference is about 60nSec. There is some lengthening of the pulse
in the noise receiver and detector, but only a uSec or so. With a little
extra delay added by using a 100nSec delay line, the blanking pulses will
precede the noise impulses by about 40nSec, which should compensate for any
minor temperature variation in either direction.

One serious problem I came across in the literature was that with the IF
noise blankers the noise impulses were lengthened by ringing in the
narrow-band IF. When you lengthen the blanking pulses to match the
lengthened noise impulses, the blanking becomes audible. By keeping
everything prior to the receiver and paying close attention to the noise
receiver delay and pulse "stretching", this should not become a serious
problem as with the IF noise blankers.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2803 2009-03-27 07:51:16 timshoppa Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
2804 2009-03-27 08:24:31 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
>> I prototyped two different approaches. The first one would have
>> required about 3,600 meters of cable for the time delay
>> equalization. Not
>> good. This one needs just 15-20 meters. Not perfect, but certainly
>> better.
>
> Decades ago, there were special coax cables that had ridiculously high
> inductance per unit length that made very very good delay lines. They
> may have made your "3600 meter of cable" version more tractable.
>
> My understanding is that they were basically a series of ferrite cores.
>
> Have no idea where to buy it, probably hasn't been made in most of a
> century.
>

It may still be around somewhere. I've been digging into all sorts of literature about distributed delay lines for days. One method is a dielectric and ferrite filled tube that has the appearance of a high inductance/meter and capacitance/meter transmission line, which sounds like the one you are talking about. Another is the shielded helical transmission line. I've only found this by way of patents so far and have yet to do a non-patent literature search.

The delay lines from Data Delay Devices may be the best option, despite their cost, and the 50' cable may be the most convenient. There are lumped element solutions, but they are a bit ambitious. I'm still looking for a convenient, inexpensive solution, but those may be mutually exclusive.



Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_
2805 2009-03-27 10:03:34 Dave Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
2806 2009-03-27 15:33:41 WB6TPU Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
2822 2009-03-30 07:18:32 victorkoren Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
Chris,
I'm trying to read your PDF document but I get a "corrupted PDF file" from the adobe reader. Is it still posted?
And yes, I'm using the right web address.
Victor - 4Z4ME
2826 2009-03-30 07:50:52 Chris Trask Re: The Solder Wick Chronicles, Part 1: The Iron, the Bench, and the
>
>Chris,
>I'm trying to read your PDF document but I get a "corrupted PDF file" from the adobe reader. Is it still posted?
>And yes, I'm using the right web address.
>

I can download it just fine.



Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_