Post by thread:[EE]:F-set or Cable tracer

I just bought a kit to make my own F-Set, and I am having problems with the probe. Its basicly a 2N5484 FET followed by a bc549 feeding a LM386 amp which detects the signal radiated by a tone generator based on a pair of 555s. Does anyone have or know where I can look at a circuit diagram for a similar product? The kit has only a circuit diagram which does not match the parts or the PCB. Foolishly I assembled it by following the PCB, which may or may not be correct. -- CW. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

part 0 44 bytes his is a multi-part message in MIME format. part 1 961 bytes content-type:text/plain; charset=us-ascii (decoded 7bit) I had a friend that worked for the local phone company. He lent me his fox/hound and I reversed engineered it. Here is the hound........ (Fox is also available if you need it.) Rick Chris Wheeler wrote: {Quote hidden}> I just bought a kit to make my own F-Set, and I am having problems with > the > probe. > > Its basicly a 2N5484 FET followed by a bc549 feeding a LM386 amp which > detects the signal radiated by a tone generator based on a pair of 555s. > > Does anyone have or know where I can look at a circuit diagram for a > similar > product? > The kit has only a circuit diagram which does not match the parts or the > PCB. Foolishly I assembled it by following the PCB, which may or may > not be > correct. > > -- > CW. > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body part 2 7188 bytes content-type:image/gif; (decode) part 3 136 bytes -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

> I had a friend that worked for the local phone company. He lent me his > fox/hound and I reversed engineered it. Here is the hound........ (Fox is > also available if you need it.) > Rick Thanks Rick. Hmmm that is a lot less complex design than the one I have. What FET would you recommend? The design I have has the 2N5484 which has the lowest Ig and Vgs in the chart I have. I would appreciate the curcuit for the fox too. -- CW -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

Okay, I'm sure this was covered in Elect 101 while I was sleeping (which was most of the time since I thought the whole class was a review) but what is a fox/hound? {Quote hidden}> I had a friend that worked for the local phone company. He lent me his > fox/hound and I reversed engineered it. Here is the hound........ > (Fox is > also available if you need it.) > Rick > > Chris Wheeler wrote: > > > I just bought a kit to make my own F-Set, and I am having problems with > > the > > probe. > > > > Its basicly a 2N5484 FET followed by a bc549 feeding a LM386 amp which > > detects the signal radiated by a tone generator based on a pair of 555s. > > > > Does anyone have or know where I can look at a circuit diagram for a > > similar > > product? > > The kit has only a circuit diagram which does not match the parts or the > > PCB. Foolishly I assembled it by following the PCB, which may or may > > not be > > correct. > > > > -- > > CW. > > > > -- > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

For this purpose, any N ch JFET will work. Even the MPF102. Rick Chris Wheeler wrote: {Quote hidden}> > I had a friend that worked for the local phone company. He lent me his > > fox/hound and I reversed engineered it. Here is the hound........ (Fox > is > > also available if you need it.) > > Rick > > Thanks Rick. > > Hmmm that is a lot less complex design than the one I have. > What FET would you recommend? The design I have has the 2N5484 which has the > lowest Ig and Vgs in the chart I have. > > I would appreciate the curcuit for the fox too. > > -- > CW > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email @spam@listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email KILLspamlistservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

The phone lineman use a tone generating device to trace a single line in a bundle of pairs. They put a tone generator module (fox), rich in square waves, at one end or one place in a building, and take the detector (hound) and sniff all the wires at another part of a building. A strong howl coming from a pair, even without touching the cable, can be detected. The stronger the signal on a pair, the more likely you have the right one. I've seen these units sold in some of the more well-stocked hardware stores. Rick Nelson Hochberg wrote: {Quote hidden}> Okay, I'm sure this was covered in Elect 101 while I was sleeping (which > was most of the time since I thought the whole class was a review) but what > is a fox/hound? > > > I had a friend that worked for the local phone company. He lent me his > > fox/hound and I reversed engineered it. Here is the hound........ > > (Fox is > > also available if you need it.) > > Rick > > > > Chris Wheeler wrote: > > > > > I just bought a kit to make my own F-Set, and I am having problems with > > > the > > > probe. > > > > > > Its basicly a 2N5484 FET followed by a bc549 feeding a LM386 amp which > > > detects the signal radiated by a tone generator based on a pair of 555s. > > > > > > Does anyone have or know where I can look at a circuit diagram for a > > > similar > > > product? > > > The kit has only a circuit diagram which does not match the parts or the > > > PCB. Foolishly I assembled it by following the PCB, which may or may > > > not be > > > correct. > > > > > > -- > > > CW. > > > > > > -- > > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > > email RemoveMElistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body > > > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email spamBeGonelistservspamBeGonemitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email TakeThisOuTlistservEraseMEspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

Here are two sites...... http://www.elexp.com/tst_fox.htm http://www.jdr.com/interact/item.asp?itemno=gr-fox-hound Rick Nelson Hochberg wrote: {Quote hidden}> Okay, I'm sure this was covered in Elect 101 while I was sleeping (which > was most of the time since I thought the whole class was a review) but what > is a fox/hound? > > > I had a friend that worked for the local phone company. He lent me his > > fox/hound and I reversed engineered it. Here is the hound........ > > (Fox is > > also available if you need it.) > > Rick > > > > Chris Wheeler wrote: > > > > > I just bought a kit to make my own F-Set, and I am having problems with > > > the > > > probe. > > > > > > Its basicly a 2N5484 FET followed by a bc549 feeding a LM386 amp which > > > detects the signal radiated by a tone generator based on a pair of 555s. > > > > > > Does anyone have or know where I can look at a circuit diagram for a > > > similar > > > product? > > > The kit has only a circuit diagram which does not match the parts or the > > > PCB. Foolishly I assembled it by following the PCB, which may or may > > > not be > > > correct. > > > > > > -- > > > CW. > > > > > > -- > > > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > > > email RemoveMElistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body > > > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listservEraseME.....mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservmitvma.mit.edu with SET PICList DIGEST in the body

part 0 44 bytes his is a multi-part message in MIME format. part 1 891 bytes content-type:text/plain; charset=us-ascii (decoded 7bit) Enclosed is the FOX. I layed out circuit boards for both. Just a little bigger than a postage stamp. Contact me off post if you are interested. Rick Chris Wheeler wrote: {Quote hidden}> > I had a friend that worked for the local phone company. He lent me his > > fox/hound and I reversed engineered it. Here is the hound........ (Fox > is > > also available if you need it.) > > Rick > > Thanks Rick. > > Hmmm that is a lot less complex design than the one I have. > What FET would you recommend? The design I have has the 2N5484 which has the > lowest Ig and Vgs in the chart I have. > > I would appreciate the curcuit for the fox too. > > -- > CW > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email RemoveMElistservEraseMEEraseMEmitvma.mit.edu with SET PICList DIGEST in the body part 2 5011 bytes content-type:image/gif; (decode) part 3 136 bytes -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservspam_OUTKILLspammitvma.mit.edu with SET PICList DIGEST in the body

A cable tracer kit is going to be published in the october, 2002 edition of Silicon Chip, the Australian electronics magazine. You can read it at http://www.kitsrus.com/pdf/k181_article.pdf you can buy it from Oatley Electronics in Sydney for about $US12 plus postage. regards, Peter Crowcroft DIY Electronics (HK) Ltd PO Box 88458, Sham Shui Po, Hong Kong Factory: voice 852-2304 2250 Fax: 852-2729 1400 M/F, 97 Fuk Wa Street, Sham Shui Po Home: voice 852-2720 0255 Mobile: 6273 2049 Web: http://www.kitsrus.com Email: EraseMEpeterspamspamBeGonekitsrus.com Yahoo Messenger 'peter5999' with webcam ------------------------------------------------------------- -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestKILLspammitvma.mit.edu

From: "Peter Crowcroft" <peterSTOPspamspam_OUTKITSRUS.COM> > A cable tracer kit is going to be published in the october, 2002 edition of > Silicon Chip, the Australian electronics magazine. > > You can read it at > > http://www.kitsrus.com/pdf/k181_article.pdf This is the one I bought and built. Very dissapointed that all I got was the schematic and the bits. The pcb looked second rate too. I possibly just got unlucky and got the dud one. I'm going to break the one I built down and make sure there were no mistakes, and test the LM386 and the two 555s Thanks for the PDF. Postscipt: I checked the fox against both schmatics and the schematic has pins 1 and 4 of the 555 to gnd, pcb does not (correct). Both schematics disagree with the layout and have the C8050 with the emitter and collector reversed (assuming of couse that the pinout shown in the article is correct on page 2) -- CW -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

HA! Thought so. The article has the C8050 pinout the wrong way around. http://www.ushasemi.com/pdf/Transistors/C8050.pdf Pins correct for the BC549 tho. http://www.electronicsplanet.ch/Praxis/datenbla/BC549.pdf The other circuit has inconsistancies too. There is a 220 ohm resistor between the capacitor on Q3's emitter and gnd. I don't see it on the schematic, but its there on the the PCB. I'm building the circuits on a breadboard with fresh parts to work out where the problem is. So far I've verified the 555s work and the first stage is oscillating. > I checked the fox against both schmatics and the schematic has pins 1 and 4 > of the 555 to gnd, pcb does not (correct). Both schematics disagree with the > layout and have the C8050 with the emitter and collector reversed (assuming {Quote hidden}> of couse that the pinout shown in the article is correct on page 2) > > > -- > CW > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

From: "Chris Wheeler" <spamBeGonecwheeler2STOPspamEraseMETELSTRA.COM> > HA! Thought so. The article has the C8050 pinout the wrong way around. > http://www.ushasemi.com/pdf/Transistors/C8050.pdf > > Pins correct for the BC549 tho. > http://www.electronicsplanet.ch/Praxis/datenbla/BC549.pdf > > The other circuit has inconsistancies too. There is a 220 ohm resistor > between the capacitor on Q3's emitter and gnd. I don't see it on the > schematic, but its there on the the PCB. > > I'm building the circuits on a breadboard with fresh parts to work out where > the problem is. So far I've verified the 555s work and the first stage is > oscillating. I tested the LM386 on breadboard and made a crude amp from the data sheet. I've been able to verify The Fox works now on the pcb. The probe PCB still wont amplify, so I'm planning to build the circuit up on the breadboard, and if it works as advertised, then the PCB must be open somewhere. I built the other probe that Rick C posted and that works. I've had to compromise with the component values, 220ohm and 270ohm rather than the 240 and 260 in his circuit. It works very well. -- CW -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

>I tested the LM386 on breadboard and made a crude amp from the data sheet. >I've been able to verify The Fox works now on the pcb. > >The probe PCB still wont amplify, so I'm planning to build the circuit up on >the breadboard, and if it works as advertised, then the PCB must be open >somewhere. LM386 are known to be temperamental. Use a scope to check for oscillation. Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.