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#1
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Sort of boat anchor
Hi gang,
I'm looking for the schematic of the old Archer "Space Patrol" walkie talkie or similar. I think this tpye all used a very similar circuit with a superregenerative rx that used the same stage as a non-crystal controlled oscillator on tx along with a 2(?) stage audio amp. Any help? Tnx Bob WB0POQ |
#2
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Sort of boat anchor
Bob wrote:
I'm looking for the schematic of the old Archer "Space Patrol" walkie talkie or similar. I think this tpye all used a very similar circuit with a superregenerative rx that used the same stage as a non-crystal controlled oscillator on tx along with a 2(?) stage audio amp. A lot of companies in Japan made these things, and they all copied one another in much the way Chinese manufacturers do today. Here's a typical design: http://yb3td.com/data/walkietalkie.html As I recall, the Archers that I had as a kid were crystal-controlled for transmit but used an adjustable LC network for receive tuning. I remember moving one to 10M at one point but the audio quality was very bad and of course there was no squelch... --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#3
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Sort of boat anchor
Hi Scott,
Thanks for the response. I found that site a few days ago, and was playing around trying to get that circuit to work, until I noticed that there is no DC path for collector current for Q1. Also, there seems to be an issue with how L1 and L2 and the associated caps are connected. I moved a few things around and got Q1 to work as an oscillator and a superregen detector (I think), but have not built up the audio and the switching circuits yet. I'm still hoping to find some other examples of these cute little rigs. Bob "Scott Dorsey" wrote in message ... Bob wrote: I'm looking for the schematic of the old Archer "Space Patrol" walkie talkie or similar. I think this tpye all used a very similar circuit with a superregenerative rx that used the same stage as a non-crystal controlled oscillator on tx along with a 2(?) stage audio amp. A lot of companies in Japan made these things, and they all copied one another in much the way Chinese manufacturers do today. Here's a typical design: http://yb3td.com/data/walkietalkie.html As I recall, the Archers that I had as a kid were crystal-controlled for transmit but used an adjustable LC network for receive tuning. I remember moving one to 10M at one point but the audio quality was very bad and of course there was no squelch... --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#4
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Sort of boat anchor
In article , b wrote:
Thanks for the response. I found that site a few days ago, and was playing around trying to get that circuit to work, until I noticed that there is no DC path for collector current for Q1. Hmm... you're right, that's really creepy. You think maybe base and collector are swapped here? I was thinking at first that maybe the base leakage did the trick, which could be possible if it's a germanium type. Also, there seems to be an issue with how L1 and L2 and the associated caps are connected. I moved a few things around and got Q1 to work as an oscillator and a superregen detector (I think), but have not built up the audio and the switching circuits yet. I'm still hoping to find some other examples of these cute little rigs. I can send you a Lafayette one if I can find it. You're welcome to draw the schematic out. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#5
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Sort of boat anchor
Scott,
I don't think the base and collector are swapped as the biasing looks right as drawn on the presumed base, plus, if so then there would be no path for base current. Thanks for the offer of the Lafayette, I'd love to get a look at it. Bob "Scott Dorsey" wrote in message ... In article , b wrote: Thanks for the response. I found that site a few days ago, and was playing around trying to get that circuit to work, until I noticed that there is no DC path for collector current for Q1. Hmm... you're right, that's really creepy. You think maybe base and collector are swapped here? I was thinking at first that maybe the base leakage did the trick, which could be possible if it's a germanium type. Also, there seems to be an issue with how L1 and L2 and the associated caps are connected. I moved a few things around and got Q1 to work as an oscillator and a superregen detector (I think), but have not built up the audio and the switching circuits yet. I'm still hoping to find some other examples of these cute little rigs. I can send you a Lafayette one if I can find it. You're welcome to draw the schematic out. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#6
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Sort of boat anchor
In article , b wrote:
Scott, I don't think the base and collector are swapped as the biasing looks right as drawn on the presumed base, plus, if so then there would be no path for base current. Thanks for the offer of the Lafayette, I'd love to get a look at it. Give me an address and I will mail it. Your email in your post is not valid. Looking inside it, it looks way higher quality than the Archer. It has two transformers inside! --scott I will say, though, that the RF performance on the Teenage Mutant Ninja Turtle 49 Mhz walkie-talkie when moved to 6M is much better than on the Archer Space Cadet walkie-talkie when moved to 10M. Either one is really fun to write on a QSL card, though. -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#7
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Sort of boat anchor
On Thu, 10 Dec 2009, Scott Dorsey wrote:
In article , b wrote: Thanks for the response. I found that site a few days ago, and was playing around trying to get that circuit to work, until I noticed that there is no DC path for collector current for Q1. Hmm... you're right, that's really creepy. You think maybe base and collector are swapped here? I was thinking at first that maybe the base leakage did the trick, which could be possible if it's a germanium type. Also, there seems to be an issue with how L1 and L2 and the associated caps are connected. I moved a few things around and got Q1 to work as an oscillator and a superregen detector (I think), but have not built up the audio and the switching circuits yet. I'm still hoping to find some other examples of these cute little rigs. I can send you a Lafayette one if I can find it. You're welcome to draw the schematic out. I think you're right, the circuits were so simple that there wasn't much variation. Any schematic, I suspect they are in the RCA transistor guides among other places) would make a good start for circuit tracing. You have an end circuit to visualize and use the actual circuitry to "test" the schematic, either it's going to match or be close. Michael VE2BVW |
#8
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Sort of boat anchor
In article , b wrote:
Scott, I don't think the base and collector are swapped as the biasing looks right as drawn on the presumed base, plus, if so then there would be no path for base current. Thanks for the offer of the Lafayette, I'd love to get a look at it. No joke. Get me your physical mailing address and I'll send it to you. But you have to email me your address. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#9
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Sort of boat anchor
* I'm looking for the schematic of the old Archer "Space Patrol" walkie
talkie or similar. *I think this tpye all used a very similar circuit with a superregenerative rx that used the same stage as a non-crystal controlled oscillator on tx along with a 2(?) stage audio amp. I can email scanned pages of the entire "manual" (two pages!-) of the Archer 60-4005 "Space Patrol Walkie Talkie" or I can put them on my website and let you snarf them yourself. Your call. --W0PBV. |
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