++++++++++++++++++ From: "Don Brown" To: "Tom Buchanan" , "Elecraft" Subject: Re: [Elecraft] Freq. counter probe capacitor Date: Mon, 7 Oct 2002 16:38:35 -0500 Hi The cap is in one of the little brown bags it is an axial lead cap a litt= le smaller than a grain of rice with 2 leads out of each end. look again = you may have overlooked it. Don Brown KD5NDB ----- Original Message ----- From: Tom Buchanan Sent: Monday, October 07, 2002 4:01 PM To: elecraft at mailman.qth.net Subject: [Elecraft] Freq. counter probe capacitor I couldn't find the 10 pF axial lead cap in the misc. bag for the freq. counter probe. Looking for some clarification before I proceed...is this referring to a ceramic disc type cap or an axial lead electrolytic? Figu= re 6 -14 on page 44 of the K2 manual doesn't really resemble a disc type and= I just wanted to be sure before heading off to the electronics store. K2 #2688 powered up for the first time a couple of days ago with the firs= t test :) 73, Tom KG4KGY +++++++++++++++ From: "=?iso-8859-1?B?V9hJRkw=?=" To: "Elecraft" Subject: Re: [Elecraft] Freq. counter probe capacitor Date: Mon, 7 Oct 2002 16:51:46 -0500 I remember watching in horror as I heated that little "piece of rice" just a little too much and it fell right off of it's leads! A trip to Tom's house (N0SS) and I had a replacement. Remember that, Tom??? My point is: Be really careful, a little heat goes too far with that little cap! Assuming you do find it, that is.. GL! Ron E. +++++++++++++++ From: "james h edwards" To: Date: Sun, 6 Oct 2002 06:49:39 -0700 Subject: [Elecraft] counter probe I also have lost my probe as i built the k2100 kit would a disk 10pf cap do or should i order it from elecraft still very happy with my k2,n5tog 73`s harold +++++++++++++++++ Date: Mon, 07 Oct 2002 17:57:13 -0500 To: "james h edwards" , elecraft at mailman.qth.net From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] counter probe At 08:49 AM 10/6/02, you wrote: >I also have lost my probe as i built the k2100 kit would a disk 10pf cap do >or should i order it from elecraft still very happy with my k2,n5tog 73`s >harold ANY 10pF (or close) cap should work. That particular cap was chosen (I believe) because it allowed a more streamlined design, rather than looking like a pregnant guppy. 73, Tom N0SS +++++++++++++++ From: "Bill Magruder" To: Date: Mon, 7 Oct 2002 18:20:52 -0700 Organization: Microsoft Corporation Subject: [Elecraft] Freq. counter probe capacitor Just completed mine counter probe. Look in the little yellow bag. The bag should have the tip a couple glass diodes along with the cap. axial cap, grain of rice describes the size, yellowish orange, with 10j marking. I headed the advice of the other reply and I soldered the cap to the center conductor of the coax quickly. Then on the tip side I put a heat sink between the cap and the tip. The mass of the tip must be 10 times the mass of the cap and I didn't want to melt the cap. It took quite a bit of heat on the tip to get a good joint. Bill KD7KST +++++++++++++++ From: "Don Brown" To: "Elecraft" Subject: Re: [Elecraft] Freq. counter probe capacitor Date: Tue, 8 Oct 2002 07:40:44 -0500 Hi When building the probe hold the tip in a small vice or a alligator clip = and fill the cup with solder (you can also wrap several turns of rubber b= and around the handles of your needle nose pliers to hold them closed gri= pping the probe tip). Clip and quickly tin the cap leads. Then heating on= ly the probe tip insert the cap into the cup. Pre tin the center conducto= r of the cable and quickly tack solder the cap and center conductor. This= should prevent overheating the cap. Don Brown KD5NDB ++++++++++++++ From: "Don Brown" To: "james h edwards" , "Elecraft" Subject: Re: [Elecraft] counter probe Date: Tue, 8 Oct 2002 07:55:46 -0500 Hi A disk cap would not fit into the probe very well even though it would wo= rk. You can order a replacement probe kit from Elecraft. It includes the = connector parts, cable, tip and cap. Lost probes may be more common now t= hat Elecraft does not recommend leaving it connected when the KPA100 is i= nstalled. I think I will use one of those small zip lock bags to store mi= ne and tape the bag to the side panel or the shield on the KPA100 inside = the K2 so I won't loose it ;-) Don Brown KD5NDB ----- Original Message ----- From: james h edwards Sent: Tuesday, October 08, 2002 2:41 AM To: Elecraft at mailman.qth.net Subject: [Elecraft] counter probe I also have lost my probe as i built the k2100 kit would a disk 10pf cap = do or should i order it from elecraft still very happy with my k2,n5tog 7= 3`s harold +++++++++++++++++ Date: Tue, 08 Oct 2002 08:29:29 -0500 To: "Elecraft" From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Freq. counter probe capacitor At 07:40 AM 10/8/02, Don Brown wrote: >When building the probe hold the tip in a small vice or a alligator clip >and fill the cup with solder (you can also wrap several turns of rubber >band around the handles of your needle nose pliers to hold them closed >gripping the probe tip). Clip and quickly tin the cap leads. Then heating >only the probe tip insert the cap into the cup. Pre tin the center >conductor of the cable and quickly tack solder the cap and center >conductor. This should prevent overheating the cap. Good reminder, Don. Another device which I find to be a "MUST HAVE" for any builder (anyone soldering to solid state devices), is at least one pair of hemostats (medical term for the long, slender, plier-like locking clamps used in hospitals). Hemostats are lightweight, have a nice long, slender nose, and can be locked so they don't release when you remove your fingers from them. They can easily hold on to the lead of a temperature-sensitive component as you are soldering it, to help 'sink' away the hear before it can get to the device and possibly damage it. Fortunately, most devices nowadays are pretty sturdy when it comes to their ability to withstand a bit of soldering heat without self-destructing. But my hemostats ALWAYS come into play when I'm trying to solder to a short piece of shield braid coming from a length of RG-174 (the small diameter coax cable). Without a hemostat secured BETWEEN the body of the coax and the point on the shield being soldered to, the heat from soldering will run right down the shield, melt the center insulation of the coax and can cause a short between the two conductors. RG-174 and similar type cables (incl. audio cables) are particularly bad for being susceptible to such damage from soldering if some sort of heatsink is not provided during soldering. Additionally, I cannot count the number of times I've used one or more pairs of hemostats to hold a component (or wire) steady while I was either tinning or soldering it to something else. They're invaluable! And, they can often be found for a very reasonable price at hamfests. Try to find the type of hemostat which has a 3/4" to 1" long nose and which is easy to open/close/lock. Some hemostats are much too strong and will apply excessive compression on components and their leads. I once bought a pair of hemostats with a really short (3.8") nose. They were made in Pakistan, but the price ($2.50) was right. Got them home and tried them out. First use... the nose BENT and stayed bent when they were released. Turns out these particular hemostats (actually, I think these should probably have been called 'pickups') were specifically used for catching suture thread and weren't intended for the same type of use as regular hemostats as they were only designed for holding threads and not anything larger. I certainly would NOT recommend use of this type of the device. I probably now have 8 set of hemostats, of all different sizes ands lengths. They have all seen heavy use over the past 30 or so years. HIGHLY RECOMMENDED for builders. 73, Tom Hammond N0SS ++++++++++++++++ Date: Tue, 08 Oct 2002 08:29:29 -0500 To: "Elecraft" From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Freq. counter probe capacitor At 07:40 AM 10/8/02, Don Brown wrote: >When building the probe hold the tip in a small vice or a alligator clip >and fill the cup with solder (you can also wrap several turns of rubber >band around the handles of your needle nose pliers to hold them closed >gripping the probe tip). Clip and quickly tin the cap leads. Then heating >only the probe tip insert the cap into the cup. Pre tin the center >conductor of the cable and quickly tack solder the cap and center >conductor. This should prevent overheating the cap. Good reminder, Dan. Another device which I find to be a "MUST HAVE" for any builder (anyone soldering to solid state devices), is at least one pair of hemostats (medical term for the long, slender, plier-like locking clamps used in hospitals). Hemostats are lightweight, have a nice long, slender nose, and can be locked so they don't release when you remove your fingers from them. They can easily hold on to the lead of a temperature-sensitive component as you are soldering it, to help 'sink' away the hear before it can get to the device and possibly damage it. Fortunately, most devices nowadays are pretty sturdy when it comes to their ability to withstand a bit of soldering heat without self-destructing. But my hemostats ALWAYS come into play when I'm trying to solder to a short piece of shield braid coming from a length of RG-174 (the small diameter coax cable). Without a hemostat secured BETWEEN the body of the coax and the point on the shield being soldered to, the heat from soldering will run right down the shield, melt the center insulation of the coax and can cause a short between the two conductors. RG-174 and similar type cables (incl. audio cables) are particularly bad for being susceptible to such damage from soldering if some sort of heatsink is not provided during soldering. Additionally, I cannot count the number of times I've used one or more pairs of hemostats to hold a component (or wire) steady while I was either tinning or soldering it to something else. They're invaluable! And, they can often be found for a very reasonable price at hamfests. Try to find the type of hemostat which has a 3/4" to 1" long nose and which is easy to open/close/lock. Some hemostats are much too strong and will apply excessive compression on components and their leads. I once bought a pair of hemostats with a really short (3.8") nose. They were made in Pakistan, but the price ($2.50) was right. Got them home and tried them out. First use... the nose BENT and stayed bent when they were released. Turns out these particular hemostats (actually, I think these should probably have been called 'pickups') were specifically used for catching suture thread and weren't intended for the same type of use as regular hemostats as they were only designed for holding threads and not anything larger. I certainly would NOT recommend use of this type of the device. I probably now have 8 set of hemostats, of all different sizes ands lengths. They have all seen heavy use over the past 30 or so years. HIGHLY RECOMMENDED for builders. 73, Tom Hammond N0SS ++++++++++++++++++ Date: Tue, 8 Oct 2002 07:57:52 -0700 From: Mike Butts To: elecraft at mailman.qth.net Subject: [Elecraft] Re: Freq. counter probe capacitor > I remember watching in horror as I heated that little "piece of rice" > just a > little too much and it fell right off of it's leads! Me too. Fortunately the C180 mod http://mailman.qth.net/pipermail/elecraft/2002-July/031226.html says leave out C180, which is a 10pf disk ceramic. Not sleek but it works OK. Use a hemostat and don't bust the nice one like I did. 73 de KC7IT K2 #2640 +++++++++++++++++++ Date: Tue, 08 Oct 2002 12:42:20 -0500 To: "elecraft at mailman.qth.net" From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] counter probe Cc: kc4kgu at ENTERZONE.NET Hi George: At 12:05 PM 10/8/02, George, W5YR wrote: >I am missing a serious point, as a new K2 owner. What is wrong with leaving >the probe in TP 2 all the time? That way CAL FIL is always available for >inspection of passbands, retuning, or whatever, without removing the top >cover. Someone will probably respond in a much more illustrative manner, but it is my understanding that leaving the FCTR probe connected to TP2 can result in some spurious signals (possibly) being transmitted... albeit at probably a very low level. For easily two years, I retained my FCTR probe in TP2... never noticed any problems. However, IF there is even a remote possibility of such spurs, and especially if the KPA100 is installed, I don't want to change having the PA (or the KPA) amplifying them and having them go out to the antenna. Just best to not risk it, even if it is a remote possibility. However, I am ADAMANT about retaining the FCTR probe INSIDE my K2... WAY too easy to either misplace or to just not have it available if I'd happen to need it while on a trip where I couldn't find/make one quickly. Two years in a row, when I was offering free Spectrogram XFIL alignments at Dayton, I had numerous K2 owners bring in their K2s without the FCTR cable and I'd have to cannibalize my K2 in order to complete their alignments... a couple times I almost left mine in their K2! 73, Tom N0SS +++++++++++++++++ Date: Tue, 08 Oct 2002 12:44:26 -0500 To: elecraft at mailman.qth.net From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] counter probe kc4kgu wrote, regarding 'storing' of the K2 FCTR probe: >Well, with the KPA100, I don't think there's room in the rig to leave >it. It would be tighter than I would want to venture at least. Other >than that, I'm not sure. When #2490 was still QRP, I used to do exactly >what you suggest. Oh, there's ample room to store it. The important thing is to keep the tip from 'floating' around aimlessly inside the case. That's why I (kinda) capture it in the 2D connector. 73, Tom N0SS ++++++++++++++++ Date: Tue, 8 Oct 2002 14:13:13 -0400 (EDT) From: kc4kgu at ENTERZONE.NET To: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Cc: Elecraft at mailman.qth.net Subject: Re: [Elecraft] counter probe On Tue, 8 Oct 2002, Tom Hammond [iso-8859-1] N=D8SS wrote: > kc4kgu wrote, regarding 'storing' of the K2 FCTR probe: >=20 > >Well, with the KPA100, I don't think there's room in the rig to leave > >it. It would be tighter than I would want to venture at least. Other > >than that, I'm not sure. When #2490 was still QRP, I used to do exactly > >what you suggest. >=20 > Oh, there's ample room to store it. The important thing is to keep the ti= p=20 > from 'floating' around aimlessly inside the case. That's why I (kinda)=20 > capture it in the 2D connector. >=20 > 73, >=20 > Tom N0SS Ahhh... The operative word here is "store". I'll have to open up the rig and find some places to hide both probes. I think a couple of "buffer tubes" from the fiber optic work should work nicely to capture both probe tips and insulate them from anything as well. 73 de John - KC4KGU K2/100 #2490 ++++++++++++++++ Date: Tue, 08 Oct 2002 13:38:37 -0500 From: "George, W5YR" Organization: AT&T WorldNet Service To: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Cc: "elecraft at mailman.qth.net" , kc4kgu at ENTERZONE.NET Subject: Re: [Elecraft] counter probe Thanks, Tom - I will do a very careful examination of the K2 output signal with this in mind. TP2 in on the BFO signal line to the transmit mixer U10. So, I can appreciate that any lack of integrity in the shielding of the FCTR probe cable could allow other signals from the RF Board to be picked up and introduced into the mixer input. I find nothing in the manual about what to do with the probe after completing CAL FIL, but perhaps something has been posted on the list. 73/72, George Amateur Radio W5YR - the Yellow Rose of Texas In the 57th year and it just keeps getting better! Fairview, TX 30 mi NE of Dallas in Collin county EM13qe K2 #489 Icom IC-765 #2349 Icom IC-756 PRO #2121 +++++++++++++++++ Date: Tue, 08 Oct 2002 13:24:49 -0700 From: Vic Rosenthal Organization: Transparent Software To: "elecraft at mailman.qth.net" Subject: Re: [Elecraft] counter probe "George, W5YR" wrote: > > Thanks, Tom - I will do a very careful examination of the K2 output signal > with this in mind. Do this test with the probe in and out: transmit on 20 meter CW and listen on 14.985 MHz (or thereabouts). You will notice a spur which is louder when the probe is in. I think it's the third harmonic of the BFO. Now, whether this can actually get radiated is a question that I can't answer. Vic K2VCO ++++++++++++++++++ Reply-To: From: "Ron D'Eau Claire" To: Subject: RE: [Elecraft] counter probe Date: Tue, 8 Oct 2002 13:54:08 -0700 I had no trouble leaving it in. I did bend the cable over a bit just above the "plug" on the r-f board so the cable didn't stick up so high. That avoided the KPA100 'squashing' the cable down and stressing the plug and jack on the r-f board. Other than that, it fits just fine! Ron AC7AC K2 # 1289 Well, with the KPA100, I don't think there's room in the rig to leave it. It would be tighter than I would want to venture at least. Other than that, I'm not sure. When #2490 was still QRP, I used to do exactly what you suggest. 73 de John - KC4KGU K2/100 #2490 +++++++++++++++++ Date: Tue, 08 Oct 2002 16:21:04 -0500 From: "George, W5YR" Organization: AT&T WorldNet Service To: rondec at easystreet.com Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] counter probe I was just chatting with Eric, WA6HHQ, on 18,132 and one of the topics that came up was how to deal with the FCTR cable. He strongly recommends *against* leaving the cable or anything plugged into TP2. Considering the location of the TP in the circuit, I can see where such a low-level signal point should NOT have an antenna connected to it! <:} So, based upon Eric's comments I will remove the cable from TP2 and avoid any possible problems. I will soon be posting a detailed description of some mods that I have engineered for the K2. Eric blessed the effort and suggested that I pass along the details. 73/72, George Amateur Radio W5YR - the Yellow Rose of Texas In the 57th year and it just keeps getting better! Fairview, TX 30 mi NE of Dallas in Collin county EM13qe K2 #489 Icom IC-765 #2349 Icom IC-756 PRO #2121 ++++++++++++++++++ Date: Tue, 12 Nov 2002 20:53:32 -0800 From: Vic Rosenthal Organization: Transparent Software To: James Fonte Cc: "Elecraft (E-mail)" Subject: Re: [Elecraft] Counter cable... James Fonte wrote: > > Are there any negative consequences to leaving the frequency-counter-cable > plugged-in to the cable-connector and TP2 -- that is, all covers in-place, > normal operation? Elecraft suggests that you don't, because harmonics of the bfo (for example 4.91 x 3 = 14.73 MHz) are radiated from the cable, and they can increase spurious outputs. I definitely noticed an increase in the 14.73 MHz spur when the cable was attached -- it went from barely perceptable in a nearby rx to relatively loud. Whether or not this causes radiation in excess of FCC specs I don't know, but I don't plug it in so as to be on the safe side. 73 Vic K2VCO Fresno CA +++++++++++++++