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I was given a very clean TR3, pwr supply and spkr. Turns out, free is the best possible price for one of these transceivers. I exhaustively messed with the soup can filter, pulled it apart, evaluated xtals, and positively determined it was W-A-Y out of tolerance, and worthless. I set it aside as a parts rig.?
That was 3 years ago. May I presume there are (still) no realistic, economic solutions to this common TR3 problem? I say ¡°economic¡± because, even if working well, it¡¯s still just a TR3. Not worth much in the way of expenditures.?
Thanks.?
--
Richard
WB5NEN
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Just yesterday I ran across this video quite by accident. If nothing else it tells you how they work. 73 -Jim NU0C On Sat, 18 Nov 2023 16:10:51 -0800 "Richard P via groups.io" <wb5nen@...> wrote: I was given a very clean TR3, pwr supply and spkr. Turns out, free is the best possible price for one of these transceivers. I exhaustively messed with the soup can filter, pulled it apart, evaluated xtals, and positively determined it was W-A-Y out of tolerance, and worthless. I set it aside as a parts rig.
That was 3 years ago. May I presume there are (still) no realistic, economic solutions to this common TR3 problem? I say ¡°economic¡± because, even if working well, it¡¯s still just a TR3. Not worth much in the way of expenditures.
Thanks.
--
Richard
WB5NEN
|
Yeah, it was interesting but the guy has no concept of marketing or promotion. ?He seems to quite obviously keep his ¡°secrets¡± away from everyone but then doesn¡¯t offer a way to buy a solution?from him. ?Seems more like an exercise in braggadocio than anything practical.?
BTW, at least with the monolithic filters, you can still possibly repair them with baking ¡ª just like with the band crystals. It involves taking the filter apart (fairly simple with a torch and wooden-jawed vise) and testing the individual crystals. I successfully repaired the narrow filter from a TR-4Cw a year or so ago. ?I found the bad crystal, baked it, tested that it was good agin, reinstalled it and re-sealed the box.
And yes, hardwood jaws won¡¯t burn on you, if you¡¯re careful.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Sat, Nov 18, 2023 at 8:31 PM, Jim Shorney < jimNU0C@...> wrote:
Just yesterday I ran across this video quite by accident.
https://youtu.be/oBiWGC0qVBQ?feature=shared
If nothing else it tells you how they work.
73
-Jim
NU0C
On Sat, 18 Nov 2023 16:10:51 -0800
"Richard P via groups.io" <wb5nen@...> wrote:
> I was given a very clean TR3, pwr supply and spkr. Turns out, free is the best possible price for one of these transceivers. I exhaustively messed with the soup can filter, pulled it apart, evaluated xtals, and positively determined it was W-A-Y out of tolerance, and worthless. I set it aside as a parts rig.
>
> That was 3 years ago. May I presume there are (still) no realistic, economic solutions to this common TR3 problem? I say ¡°economic¡± because, even if working well, it¡¯s still just a TR3. Not worth much in the way of expenditures.
>
> Thanks.
> --
> Richard
> WB5NEN
>
>
>
>
>
|
Just yesterday I ran across this video quite by accident.
If nothing else it tells you how they work.
73 -Jim NU0C He's correct about the crystal scarcity issue and cost. The EU vendor he mentioned was probably Klove Electronics in Belgium. Until recently, Klove manufactured crystals for Quartslab in the U.K. Early this year, I set out to find replacement 455 kHz BFO crystals in a HC-6/U style for a Hallicrafters SR-400A (Cyclone III) transceiver. Baking the crystals yielded no improvement -- likely due to the low BFO frequencies. The price from Klove for a USB-LSB pair was USD $250 + shipping. Not a single U.S. vendor would consider making crystals with such low frequencies in a HC-6/U holder. ICM's exit left a crippling effect for those of us who like to restore old communications gear. Paul, W9AC
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Steve, I came away with the impression of the guy with the TR-3 "soup can" filter as you did. I watched a presentation by him on his TR-3 and how he had to re-engineer it to make it work "properly." He gave no details as to what he did as if it were used for clandestine spy communications!
Just from the view of the filter in the video, my guess is it is a "ladder filter" design. There are various versions of the topology, one using identical crystals (Cohn design). A "lattice" or "half-lattice" design would have at least one tapped inductor or RF transformer.
I built a 6-resonator (commonly referred to as 6-pole filter or 12-poles for the mathematicians in the group) for a TR-4C from 9-MHz crystals purchased for about 50-cents each from Mouser. The design is basically a classic LSB ladder filter, 500-Hz wide with terminations to match the ~450-Ohms of the Drake SSB filters. Don't ask me to build one for you; the project was over 10-years ago and my eyes worked back then. You octogenarians can empathize, I am sure! Unlike Mr. Soup Can Filter Guy, I will share the design although I will have to put it in a form readable by most.
For more information on crystal filter design, see Chapter 3.4 (starting on p.3-17) of "Experimental Methods of RF Design" by Hayward (W7ZOI), Campbell (KK7B) and Larkin (W7PUA).
73, Bob K9JU
On Sunday, November 19, 2023 at 09:29:23 AM EST, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
Yeah, it was interesting but the guy has no concept of marketing or promotion. ?He seems to quite obviously keep his ¡°secrets¡± away from everyone but then doesn¡¯t offer a way to buy a solution?from him. ?Seems more like an exercise in braggadocio than anything practical.?
BTW, at least with the monolithic filters, you can still possibly repair them with baking ¡ª just like with the band crystals. It involves taking the filter apart (fairly simple with a torch and wooden-jawed vise) and testing the individual crystals. I successfully repaired the narrow filter from a TR-4Cw a year or so ago. ?I found the bad crystal, baked it, tested that it was good agin, reinstalled it and re-sealed the box.
And yes, hardwood jaws won¡¯t burn on you, if you¡¯re careful.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Sat, Nov 18, 2023 at 8:31 PM, Jim Shorney < jimNU0C@...> wrote:
Just yesterday I ran across this video quite by accident.
https://youtu.be/oBiWGC0qVBQ?feature=shared
If nothing else it tells you how they work.
73
-Jim
NU0C
On Sat, 18 Nov 2023 16:10:51 -0800
"Richard P via groups.io" <wb5nen@...> wrote:
> I was given a very clean TR3, pwr supply and spkr. Turns out, free is the best possible price for one of these transceivers. I exhaustively messed with the soup can filter, pulled it apart, evaluated xtals, and positively determined it was W-A-Y out of tolerance, and worthless. I set it aside as a parts rig.
>
> That was 3 years ago. May I presume there are (still) no realistic, economic solutions to this common TR3 problem? I say ¡°economic¡± because, even if working well, it¡¯s still just a TR3. Not worth much in the way of expenditures.
>
> Thanks.
> --
> Richard
> WB5NEN
>
>
>
>
>
|
I'd sure like to see your design!
David, doc KD4E
On 11/19/23 10:26, Bob Loving wrote:
toggle quoted message
Show quoted text
Steve, I came away with the
impression of the guy with the TR-3 "soup can" filter as you
did. I watched a presentation by him on his TR-3 and how he
had to re-engineer it to make it work "properly." He gave no
details as to what he did as if it were used for clandestine
spy communications!
Just from the view of the
filter in the video, my guess is it is a "ladder filter"
design. There are various versions of the topology, one using
identical crystals (Cohn design). A "lattice" or
"half-lattice" design would have at least one tapped inductor
or RF transformer.
I built a 6-resonator
(commonly referred to as 6-pole filter or 12-poles for the
mathematicians in the group) for a TR-4C from 9-MHz crystals
purchased for about 50-cents each from Mouser. The design is
basically a classic LSB ladder filter, 500-Hz wide with
terminations to match the ~450-Ohms of the Drake SSB filters.
Don't ask me to build one for you; the project was over
10-years ago and my eyes worked back then. You octogenarians
can empathize, I am sure! Unlike Mr. Soup Can Filter Guy, I
will share the design although I will have to put it in a form
readable by most.
For more information on
crystal filter design, see Chapter 3.4 (starting on p.3-17) of
"Experimental Methods of RF Design" by Hayward (W7ZOI),
Campbell (KK7B) and Larkin (W7PUA).
73,
Bob K9JU
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Hi Richard,
I know the guy that made the TR-3 filters video. I tried to explain to him? that one cannot simply? buy a pile Chinese crystals? of the same frequency and hope to build a? filter; that he would have? to know the in/out impedance and measure the crystals motional paramters and frequency. Then use a filter design package to? relaize a real world filter.
I don't? believe any of this was done.
Dale W4OP
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Dale,
Yes, I had seen the videos, but never felt they were a practical, repeatable way for anyone to come up with replacements for the notorious soup can filters. I can tinker together or repair a lot of things; I¡¯ve only shipped for repair one piece of ham gear in 45 years; but xtal filter design and construction just does not appeal to me. As Clint Eastwood said, a man¡¯s gotta know his limits¡
--
Richard
WB5NEN
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Interesting things, crystals.
I used to work in a telephone equipment factory. We made our own crystals and
crystal filters. The first step of grinding the blanks...
.... There was this giant kettle looking thing. Maybe 4 feet in diameter. It was filled
with an abrasive slurry. At the top was a rotating plate and over that another plate filled
with crystal-sized holes. They would load the blanks in and the whole thing would turn like a
merry go round, getting the crystals rough tuned.
As the crystals were ground, they would emit RF. Because they were...well.. crystals.
People monitored the rough frequency with a Hallicrafters short wave radio clipped to the kettle.
A final adjustment was performed with the Dual Chamber Frequency plater. It had two chambers,
and production workers would load chamber 1 while it was plating in chamber 2. Frequency was monitored
with an HP vector volt meter. At resonance, the phase would swing through zero, and the system would
stop plating, and the chamber would open, and the other one would close.
As an instrument shop tech, I did a bit of work on both of these systems - troubleshooting the Hallicrafters for the rough step, and the vector voltmeter on the plater. The vector voltmeter had
four HP hot carrier diodes in its probe. Those matched sets of four were mondo expensive, and I saved
us some money by matching diodes with an HPIB-controlled voltmeter, controlled by a program that I
wrote on an HP9825 desktop computer.
Ah, youth.
- Jerry, KF6VB
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I know that one of the crystal suppliers I visited in the 80s (Valpey? NEL?) used the Radio Shack DX160's for the same purpose.
I recall seeing them above? turntable-looking fixtures where each operator sat doing rough adjustments.
John
On Sun, Nov 19, 2023 at 8:38?PM jerry-KF6VB < jerry@...> wrote: Interesting things, crystals.
? ? I used to work in a telephone equipment factory.? We made our own
crystals and
crystal filters.? The first step of grinding the blanks...
.... There was this giant kettle looking thing.? Maybe 4 feet in
diameter.? It was filled
with an abrasive slurry.? At the top was a rotating plate and over that
another plate filled
with crystal-sized holes.? They would load the blanks in and the whole
thing would turn like a
merry go round, getting the crystals rough tuned.
? ?As the crystals were ground, they would emit RF.? Because they
were...well.. crystals.
People monitored the rough frequency with a Hallicrafters short wave
radio clipped to the kettle.
? ?A final adjustment was performed with the Dual Chamber Frequency
plater.? It had two chambers,
and production workers would load chamber 1 while it was plating in
chamber 2.? Frequency was monitored
with an HP vector volt meter.? At resonance, the phase would swing
through zero, and the system would
stop plating, and the chamber would open, and the other one would close.
? ?As an instrument shop tech, I did a bit of work on both of these
systems - troubleshooting the Hallicrafters for the rough step, and the
vector voltmeter on the plater.? The vector voltmeter had
four HP hot carrier diodes in its probe.? Those matched sets of four
were mondo expensive, and I saved
us some money by matching diodes with an HPIB-controlled voltmeter,
controlled by a program that I
wrote on an HP9825 desktop computer.
? ?Ah, youth.
? ? ? ? ? ? ? ? - Jerry, KF6VB
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Has anyone successfully transplanted filters from a TR-4/4c into a TR-3? ?I have a nice TR-3 and a trashed TR-4 for a donor. ?
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I resurrected this thread because I've got a couple of nice TR-3s? with not so good soup can xtal filters.? I also have a wrecked TR-4, mid to early production, with the single filter box.? I think it's made by Network Sciences or something like that.? It's NOT the soup can.? I've made an attempt to transplant this filter into one of the TR-3s.? Specifically I transplanted the filter, selector switch, and both the T-6 and T-13 trimmers with the same resistor across the trimmer posts on the filter side of the trimmers.? On the opposite side of the trimmers I've left everything intact on the TR-3.? There are two leads off the selector switch that are the same as the those from the soup can and connect to the band switch in the same place on both radios.??
?
With this done the radio powers up, there's the usual wait for the tubes to warm, then the familiar sound of receive static starts to emerge from the speaker and then... nothing.? Something in the receive chain shuts down.? The selector lights function and follow the position of the selector switch as they should.? I can power the radio off and turn it back on and get the same series of events.??
?
Not sure where to take this experiment from here.? I have no way of knowing if the TR-4 filter is even any good.? Looking for suggestions or, better yet, some comments from someone that has done this upgrade.
?
Barry
KJ5GQM
|
Well sometimes a break from the task and coming back with fresh eyes helps. ?I didn¡¯t realize it but my function switch was on x-CE closing my transmit relay. I had the radio upside down and never heard it and it¡¯s hard to tell the setting with the radio upside down and no knobs or faceplate on it. ?Good news is my TR-3 has a beautiful passband on either side of the carrier now in my spectrum analyzer. I¡¯m cautiously optimistic about this transplant operation.?
On Tuesday, February 11, 2025 at 03:09:52 PM CST, Barry KJ5GQM via groups.io <chasbg@...> wrote:
I resurrected this thread because I've got a couple of nice TR-3s? with not so good soup can xtal filters.? I also have a wrecked TR-4, mid to early production, with the single filter box.? I think it's made by Network Sciences or something like that.? It's NOT the soup can.? I've made an attempt to transplant this filter into one of the TR-3s.? Specifically I transplanted the filter, selector switch, and both the T-6 and T-13 trimmers with the same resistor across the trimmer posts on the filter side of the trimmers.? On the opposite side of the trimmers I've left everything intact on the TR-3.? There are two leads off the selector switch that are the same as the those from the soup can and connect to the band switch in the same place on both radios.??
?
With this done the radio powers up, there's the usual wait for the tubes to warm, then the familiar sound of receive static starts to emerge from the speaker and then... nothing.? Something in the receive chain shuts down.? The selector lights function and follow the position of the selector switch as they should.? I can power the radio off and turn it back on and get the same series of events.??
?
Not sure where to take this experiment from here.? I have no way of knowing if the TR-4 filter is even any good.? Looking for suggestions or, better yet, some comments from someone that has done this upgrade.
?
Barry
KJ5GQM
|
Jim Shorney
Paul Christensen
DavidC KD4E