Re: Interesting observation concerning crystals...
The ProgRock2's are $18 each (same as the QRP Labs site), and shipping is $5 (total).? I ship stuff in little boxes, rather than padded envelopes, which raises the cost a little but nothing arrives smashed by post office processing equipment.? Total is $59.
Is the shipping address correct on QRZ?? I'm good on QRZ as well.? Just a check in the mail is preferred, and I will send this out right away.??
If anyone else ever needs ProgRock2's, I have a plentiful stock -- no need to order from Turkey.
73 - Steve, KW4H
On Friday, March 14th, 2025 at 3:39 PM, Tom Smith <n5ama@...> wrote:
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Steve, that sounds great. I’m not sure how the Beckman will respond to a square wave but it’s certainly worth a try. I would like to buy 3 of them. What is your preferred payment method and what shipping costs do I need to include to Texas (77429)?
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Thanks,
Tom N5AMA
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SX-62 alignment instructions
Hi Guys,
In the instructions it says to connect a .1mfd capacitor to pin 1 of the 7F8, do I leave the tube in circuit, or put the lead directly in the socket?
Should I remove the chassis side cover, or will it make a difference to the alignment, same with the RF shield under the IF's?
Thanks,
Scott
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Re: Interesting observation concerning crystals...
Steve, that sounds great. I’m not sure how the Beckman will respond to a square wave but it’s certainly worth a try. I would like to buy 3 of them. What is your preferred payment method and what shipping costs do I need to include to Texas (77429)?
?
Thanks,
Tom N5AMA
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I bought my first piece of radio equipment in 1957 at age 14, an
R-26/ARC-5 command set receiver. I still have it but haven't used it
for years.
I'm pondering working up a power supply for it to get it back on the
air, probably paired with my Multi-Elmac AF-67 transmitter, which is
usually paired with my S-40B.
In looking over the schematic of the R-26 and thinking about the recent
discussions of the circuitry of the S-20R and S-40B, I note a lot of
similarity between the command set receiver and the Hallicrafters. The
command set uses 12 volt tubes while the two Halli receivers use 6 volt
tubes, some of them equivalent except for the filament voltage.
The R-26 includes no band switching and covers 3-6 MHz which are the
main differences between it and the two Hallicrafters receivers. The IF
frequency in the R-26 is also much higher, at 1415 kHz, not a practical
frequency for the bandswitched Hallis with coverage down to the low end
of the BC band.
The most interesting (to me) similarity is the use of "gimmick"
capacitors in all three receivers to couple the BFO signal to the
transmission path:
S-20R C15 twisted leads to form small capacity
S-40B C38 2 mmf. "Gimmick" (in schematic)
twisted wire assembly (in parts list)
R-26 C33 <2 mmf. wiring capacitance
The S-20R also uses a "gimmick" to couple the high frequency oscillator
signal in the mixer stage (C38).
I haven't looked in detail at other makes of receivers from the '30 and
'40s, but I wonder whether the S-20R and the R-26 were just reflecting
similarities due to good engineering practice of that era, or did
someone from Hallicrafters influence the design?
73,
Maynard
W6PAP
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Re: Interesting observation concerning crystals...
Justin - you did the right thing in that SB-303.? The number of frequencies that can be readily switched with the ProgRock2 is a maximum of eight.? Technically it can output 24 pre-programmed frequencies (3 banks of 8 frequencies each), but switching the bank output when using the device to replace a heterodyne oscillator section where more than 8 crystals are involved is so difficult, it's best to just use the Arduino.? I did the same in a SB-313.
73 - Steve, KW4H
On Friday, March 14th, 2025 at 9:55 AM, Justin Bowser - KI5GKD <justin.bowser@...> wrote:
Oh, I received and SB-303 last year that had a lot of dead crystals so replaced them all with an Arduino andsi5351 module...
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/g/heathkit/message/7651
--
Justin B.
KI5GKD
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Re: Interesting observation concerning crystals...
Oh, I received and SB-303 last year that had a lot of dead crystals so replaced them all with an Arduino andsi5351 module...
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/g/heathkit/message/7651
--
Justin B.
KI5GKD
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Re: Interesting observation concerning crystals...
Steve - I don't subscribe to ER so would it be possible to e-mail me a copy of your article or post it here?
?
73,
--
Justin B.
KI5GKD
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Re: Interesting observation concerning crystals...
Tom,
I keep a fairly large stock of the ProgRock2's -- if you need some and don't want to wait for delivery from Turkey, just let me know -- you can buy them from me at the same price listed on the QRP Labs website.? I'm not officially a reseller, but ordered a bunch for use with the interface boards I designed and for other fun projects.
One thing to keep in mind about the ProgRock2 is that although it's advertised as a "programmable crystal", it's not exactly a drop-in replacement.? The ProgRock2 is, in actuality, a programmable oscillator that outputs a 3v P-P square wave, driven by a Si5351a.? In fact, you can simulate the use of a ProgRock2 by using a function generator at the frequency you're looking for, and set it for a square wave at 3v P-P.? The trick is to figure out how to integrate it in a vintage circuit.
73 - Steve, KW4H
On Friday, March 14th, 2025 at 8:08 AM, Tom Smith <n5ama@...> wrote:
Hi Steve,
Thanks for the quick reply and the offer to help. I have a complete collection of the ER magazines (have had a subscription since ER#8) and enjoy it more than any magazine I receive. I will certainly look up your article and if it looks like I can manage to program one of these devices, I will certainly order several. I’m replacing crystals in a Beckman 905 receiver that receives WWV signals from 2.5-25mhz.
?
Thanks again,
Tom N5AMA
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Re: Interesting observation concerning crystals...
Hi Steve,
Thanks for the quick reply and the offer to help. I have a complete collection of the ER magazines (have had a subscription since ER#8) and enjoy it more than any magazine I receive. I will certainly look up your article and if it looks like I can manage to program one of these devices, I will certainly order several. I’m replacing crystals in a Beckman 905 receiver that receives WWV signals from 2.5-25mhz.
?
Thanks again,
Tom N5AMA
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Re: Interesting observation concerning crystals...
Thomas,
?
I wrote an article last year called "Programmable Crystals to the Rescue", which was published in the March/April 2024 edition of ER Magazine.? That article describes in great detail how a ProgRock2 was integrated into a Heathkit HR-1680 and exactly how to program the device.? If you have access to that article, a lot of your questions will be answered.? Otherwise, I'd be happy to answer them here.? I still use the ProgRock2 for my projects when needed, and have also designed an interface board that makes it easier to integrate.
?
73 - Steve, KW4H
Tucson, AZ
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On Friday, March 14th, 2025 at 6:29 AM, Tom Smith <n5ama@...> wrote:
This package looks great and less expensive than ordering a crystal not to mention the reduced lead time. I opened the QRP Labs manual for this devise and had trouble with programming it for a specific frequency. It looks ideal to fit in a HC6/U but for a non computer savvy old timer, the programming of this devise to a specific frequency is a mystery.
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Re: Interesting observation concerning crystals...
This package looks great and less expensive than ordering a crystal not to mention the reduced lead time. I opened the QRP Labs manual for this devise and had trouble with programming it for a specific frequency. It looks ideal to fit in a HC6/U but for a non computer savvy old timer, the programming of this devise to a specific frequency is a mystery.
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Re: Interesting observation concerning crystals...
Justin -- I keep a good stock of those ProgRock2's, if you decide to go that route I can pop one into the mail to you cheaper than you ordering one from Turkey (and certainly much faster).
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73 - Steve, KW4H
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Re: Interesting observation concerning crystals...
Richard - I tried that on a heathkit SB-301 and baking woke up 2 crystals.? I just got back in from the shop re-testing the TRC-47 and that crystal is still working! :-)? The Comstat 25 originally had three crystals dead and today only one so I guess that's progress.? If the one stays dead I might replace it with a ProgRock 2...
?
73,
--
Justin B.
KI5GKD
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Re: Interesting observation concerning crystals...
What I run into more than anything else are drifted crystals, which can play havoc in circuits such as band-switched heterodyne oscillators and seriously affect dial accuracy.? I haven't tried the method you mentioned for trying to revive a dead crystal, but will give it a shot sometime!
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73 - Steve, KW4H
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Re: Interesting observation concerning crystals...
If I understand this the crystals are physically present but have
not been working. Yes, it is possible that hitting them with drive from
a signal generator may have awakened them. I would suggest that you try
baking all the "dead" crystals. Someone will correct me but I think the
temperature is around 350F for a few hours. This will sometimes wake up
dead crystals and also move drifted crystals back to their original
frequencies. Reports are that it works much of the time. The reason is
not certain but it seems to clean deposits off the surface or, perhaps
renew aged plating or soldering. Whatever is the explanation it seems to
work. It is possible that driving the crystals hard with an external
signal may accomplish a similar effect.
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On 3/11/2025 10:31 PM, Justin Bowser - KI5GKD wrote: My sickness concerning old vintage radios had morphed into revisiting
the CB radios I messed with when I was a young 'un.? I have noticed that
several have had one or more crystals out, which in a synthesized radio
one crystal is likely to take out 4 or more channels.? During my beating
on these old relics I decided to put a DDS signal generator across the
crystal, dial in it's frequency, and verify the "lost" channels were now
there and usable.? All worked as I expected except when I unhooked the
signal generator the channel was still functional!? Sometimes it would
stop working when I switched back and forth to a channel not on the
crystal, sometimes not.? The latest I tried was a Realistic TRC-47 which
is a 23 ch SSB rig and it had one crystal "dead."? I hooked up the SG
and brought the group of channels back to life and unhooked the SG.? All
channels were still alive and remained that way for the rest of the
day!? I'll see tomorrow if they still work when I turn it on.
Can someone explain this behavior?? It's almost like "goosing" the tired
crystal "repaired" it, or something.? After I get finished playing with
these old CBs I'm going to pull a Heathkit receiver off the shelf that
has a couple bad crystals and see if it will wake them up.
73,
--
Justin B.
KI5GKD
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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Interesting observation concerning crystals...
My sickness concerning old vintage radios had morphed into revisiting the CB radios I messed with when I was a young 'un.? I have noticed that several have had one or more crystals out, which in a synthesized radio one crystal is likely to take out 4 or more channels.? During my beating on these old relics I decided to put a DDS signal generator across the crystal, dial in it's frequency, and verify the "lost" channels were now there and usable.? All worked as I expected except when I unhooked the signal generator the channel was still functional!? Sometimes it would stop working when I switched back and forth to a channel not on the crystal, sometimes not.? The latest I tried was a Realistic TRC-47 which is a 23 ch SSB rig and it had one crystal "dead."? I hooked up the SG and brought the group of channels back to life and unhooked the SG.? All channels were still alive and remained that way for the rest of the day!? I'll see tomorrow if they still work when I turn it on.
?
Can someone explain this behavior?? It's almost like "goosing" the tired crystal "repaired" it, or something.? After I get finished playing with these old CBs I'm going to pull a Heathkit receiver off the shelf that has a couple bad crystals and see if it will wake them up.
?
73,
--
Justin B.
KI5GKD
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Re: Fw: Re: [HallicraftersRadios] Off-The-Wall Question
Got the manual today, very nice work.? This is the first I had ordered from you and most likely won't be the last. :-)
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73,
--
Justin B.
KI5GKD
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The only component not replaced is a large-ish mica cap buried under the LO coil assembly. I will get to that in a day or two after gently lifting the coil assembly.
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Tom
On 03/10/2025 2:23 PM PDT Jim Whartenby via groups.io <old_radio@...> wrote:
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Tom
The two original paper caps in the LO compartment are the ones that you say are still there and need to be replaced?
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What C# are they?
Jim
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Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
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Don, here's a photo of the underside in its as-found state. Not too bad but not something a sane person would plug in and turn on without at least replacing the electrolytics. Obviously it had seen some repairs over the years. I have since replaced most resistors and capacitors and replaced the old 2-wire power cord with a modern 3-wire.
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Tom
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On 03/08/2025 5:06 PM PST don Root <drootofallevil@...> wrote:
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Tom, did you mention what state it was in when you got it.. as to the components around the 6K8 . original looking? … or otherwise? ??Any mucking by somebody could have moved a connection…. and…so!
?
--
don??? va3drl
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Tom The two original paper caps in the LO compartment are the ones that you say are still there and need to be replaced?
What C# are they? Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
Don, here's a photo of the underside in its as-found state. Not too bad but not something a sane person would plug in and turn on without at least replacing the electrolytics. Obviously it had seen some repairs over the years. I have since replaced most resistors and capacitors and replaced the old 2-wire power cord with a modern 3-wire.
?
Tom
?
On 03/08/2025 5:06 PM PST don Root <drootofallevil@...> wrote:
?
?
Tom, did you mention what state it was in when you got it.. as to the components around the 6K8 . original looking? … or otherwise? ??Any mucking by somebody could have moved a connection…. and…so!
?
--
don??? va3drl
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Re: Classic Exchange - let's get these old radios on the air!
I got on the air for CX Phone this evening and received a couple interesting questions.? One was wondering why I was CQing on such an odd frequency such as 7205.525 kHz and another asking if it was possible that my transmit frequency might be changing as much as 100 Hz.? Fun questions!
There's another 45 minutes left for CX today and it'll resume on Tuesday.? CX for CW will be on Mar 30 and April 1.? Details at
If you use the spotting feature, drag the scroll bar at the bottom to the right to enter your callsign or posting won't work.
Cheers
Halden VE7UTS
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Allthumbs
Jim Whartenby