Re: [Elecraft] Elecraft KX3
On 2011-05-21 01:52 AM, Jim Balls wrote: Don't understand the use of NIMH cells with the current crop of LI-PO cells massively out perform in size, weight and capacity. Thoughts? Maybe safety concerns? Jim I favour Lithium Iron Phosphate cells because that chemistry seems to be immune to thermal runaway. (That's what I'm installing in my boat as a propulsion battery bank for an electric motor.) However, charging them properly (maintaining equal voltage in each of the cells of the battery bank) is, I think, more of a design hassle for a portable rig like the KX3 -- or whether suitably small Lithium Iron Phosphate cells are even available. I expect that the Ele-team has made a good choice given the present state of the art. Jim K7KK __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-500 Output for Input schedule?
On 2011-05-11 10:16 AM, Don Wilhelm wrote: Stan, Of course it can be driven by lower power. The KPA500 is a linear amplifier. If 40 watts in produces 500 out, then 20 in will give 250 out and 10 in will produce 125 watts. If the relationship is otherwise, then it is not acting as a linear amplifier. The same thing should be true for any linear amplifier - that is the definition of linear operation. 73, Don W3FPR Um, linear with respect to power, or linear with respect to voltage? Assuming a resistive load, P = I*I*R, or E*E/R. I *think* a linear amplifier means linear with respect to voltage (or current). If I'm wrong, I expect that I will be promptly corrected! Jim K7KK __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KX1 strikes again - Cruise Ship Bootleg Operations (OT)
U.S. hams on their own US-flagged boats are governed by FCC rule 97.11, which effectively forbids using the boat's marine HF radio also as the boat's only amateur radio. If the vessel is voluntarily equipped with a marine radio (as private yachts of any reasonable size would be), you are permitted to share the antenna, between the marine radio and the amateur radio. Unfortunately, many yachties get ham licenses and ham radios as adjuncts to their boats, and then ignore this rule. I ordered my K3 to use as my boat's ham radio. When the time comes to head offshore, I will get a proper marine SSB radio, too. Jim K7KK K3 #5263 Baba 30 sailboat #4 On 2011-04-21 01:22 PM, Mike Morrow wrote: Many hams, even the the days of the commercial Maritime Morse radio officer (which ended July 12, 1999), exhibit a cavalier attitude towards SOLAS issues. In the Morse days, for example, it is NOT likely that most hams would have recognized an SOS (which is sent as one character ...---..., not three characters ... --- ..., quite radically different in sound). Disregarding issues of ham operation upon SOLAS communications, there are regulatory issues. At sea, the country of the ship's registry would have jurisdiction over any ham operations. Are ANY cruise ships of US registry? A few, especially those that cruise in American waters only. I think Matson line may still have some passenger cruise ships. And of course, you can book passage as a passenger on many cargo ships. When in port, the host country has jurisdiction. IIRC, back in the Morse radio officer era, operation of the ship's Morse station was prohibited in port. I don't know how MF/HF USB use is controlled today in the GMDSS era. Obviously use of a ship's VHF-FM is required in foreign ports for SOLAS, piloting, and docking operations. (The only foreign country radio operation that I've ever done has been on VHF-FM as a USN officer of the deck coming in and out of port.) Do hams who operate from foreign registry ships use a call sign indicating the country of ship's registry when at sea, and a call sign of the host country when in port? I'd be surprised. I would expect the ship's master, when granting permission for a ham to operate his station on the master's ship, to insist on it. Of course, when in American waters (e.g., Alaska inside passage), an American ham would use his American call sign. I'll ask my brother-in-law about this, He is an American ham who works on Holland America Line ships as the piano player in the piano bar. Jim K7KK Many will see such issues as mere technicalities from olden days that don't apply any more. That's why it's often so difficult to get permission to operate a Ham rig on a ship - they are depending upon clear QRM-free communications on frequencies very close to several Ham bands across the HF and VHF spectrums. Plus, many QRP rigs have marginal spurious radiation specs, a situation aggravated by use of a DDS frequency generation scheme without PLL. Were I ship's master, I'd be reluctant to grant permission, based on the jurisdictional issues alone. Ron AC7AC (Licensed GMDSS Maintainer and Operator). __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KX1 strikes again - Cruise Ship Bootleg Operations (OT)
On 2011-04-21 01:53 PM, Chip Stratton wrote: Actual use of marine SSB frequencies by large commercial vessels seems to be exceedingly rare in this day of global satellite phone coverage, though there is still a requirement to carry MF/HF equipment depending on the operational distance from shore. While a ship's master may choose to prohibit your use of a QRP rig on board, the likelihood of it actually interfering with any ongoing communication at any given moment is exceedingly low to nonexistent, IMHO. If you are operating amateur maritime mobile (i.e. in international waters) I don't think there is a requirement to identify yourself with anything other than your amateur call sign. But Chip, your amateur call sign is different when on a ship of foreign registry. There *is* a requirement to be properly licensed as am amateur radio operator by the ship's country of registry (the country whose flag the ship is entitled to fly). While on the high seas on a Holland America Line ship, I would be sure to have permission (such as a reciprocal license) to show the ship's master, and would sign something like PA0/K7KK; in Canadian waters, something like K7KK/VE7 and in American waters, just K7KK or perhaps something like K7KK/KL7. On my own vessel, in international waters (outside the territorial waters of any country), I would sign something like K7KK/R2 or on phone, K7KK maritime mobile in ITU region 2. Jim K7KK K3 #5263 Baba 30 sailboat #4 Chip AE5KA GROL (but not GMDSS) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Elecraft product: XG3 All-Band RF Signal Source
You are an old English-speaking geezer (or at least an American-speaking geezer.) But the modern metric system (SI, the International System of Units) tries to name derived units after people so as to avoid the problem of cycle per second not translating well into other languages. (In not all languages does the word for cycle start with the letter c. After all, it was the French, not the English, who first introduced the metric system. That's why this English-speaking (and French- and German-reading) geezer likes to follow the metric system style guide, found at http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf. Jim, K7KK -- K3 #5263 Ignorance is the Mother of Adventure! -- Hagar the Horrible On 2011-04-14 07:24 PM, n...@n5ge.com wrote: Cycles are oscillation measurements. Mr Herz was a man who passed away many years ago. I prefer the use of cycles, because they indicate the exact type of the measurement, but I'm just an old geezer who prefers many aspects of the old days. Tom N5GE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] [K3] K3EXTREF
On 4/6/2011 5:47 AM, Dave wrote: [in an e-mail with subject Re: [Elecraft] (no subject)] Having done some long term measurements on my k3extref using an HP mHz resolution counter i have seen no corrections during transmit. Once the k3 has warmed up (first thing in the morning it would take 10 minutes for the original tcxo to stabilise enough for jt65/wspr/qrss(5Hz fsk)) I see very few corrections being made on receive either. All I need now is the release of the internal 144 xverter and I am good, frequency stability wise thro 76GHz Dave ww2r So, Dave, how did you manage to get a K3EXTREF? I would like to install one in my new K3, but as far as I can tell, it is not yet being offered for sale. I have long had an interest in the precise measurement of time and frequency, and have several 10 MHz reference oscillators. (The only time that I participated in the ARRL FMT, I was limited by ionospheric doppler, making a better measurement on the West Coast station than from W1AW on the east coast.) 73, Jim K7KK Saint Helens, Oregon, USA Remember, Ignorance is the Mother of Adventure! -- Hagar the Horrible __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [K3] Why fuse the negative lead from a battery?
On 2011-04-04 12:38 AM, Jim Brown wrote: It's critical to realize that Codes and Standards are written for specific situations. NEC applies ONLY to premises wiring, and to some extent, to wiring connected to premises wiring (like a standby generator, or an accessory building, like a garage powered from the same service). It does NOT apply to vehicles, or boats, or to the power company's wiring outside the premises. When Standards and Codes are written, very smart and experienced engineers cogitate and discuss all the possible implications of the requirements of the proposed standard, trying very hard to consider how the system would react to any of the myriad of things that might go wrong, and with serious attention both to how things are done in the real world, and to the laws of physics.For about ten years, I've been a part of that process as a member of the AES Standards Committee, and am a principal author of all of our published standards on EMC. A typical Standard takes 3-5 years to be conceived, written, and adopted. I have a great deal of respect for my colleagues, and others who do this, and for the resulting standards and codes. 73, Jim Brown K9YC Indeed. The Scope section of a standard is Very Important Indeed. So if I am to make disparaging comments about the use of NEC, it behooves me to purchase my own copy of it. Thank you for making that point. I, too, have been involved in the standards development process, first for computer codes and character sets (I was a member of ANSI X3L2, the same committee that had -- before my participation -- given us ASCII, the American National Standard Code for Information Interchange. Later I was a member of a committee under RTCA, developing standards for the use of GPS in the navigation systems of aircraft.) These people work hard, and it's a lot of fun meeting people from other companies and government agencies involved in the developing those standards. Do you know, Jim, whether the definition of premises in the NEC would include an entire marina? Not the boats kept in the marina, but the wiring of such structures as floating docks? 73, Jim Maynard K7KK __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [K3] Why fuse the negative lead from a battery?
Not completely off-topic, Joe. It bears on why I am wiring my boat to ABYC standards rather than the model National Electric Code (NEC) from the National Fire Protection Association (NFPA) -- and on why I am *not* fusing the negative lead in runs from my batteries to branch circuits such as the one that feeds my ham equipment. The recent additions to the ABYC E-11 standard (effective July 2009) requiring ELCIs (Equipment Leakage Circuit Interrupters) were added as a result of a similar ESD incident some years ago here in the Portland, Oregon area. Kids were floating downstream past a local marina's docks to cool off on a hot summer day. One of them, 12-year old Lucas Ritz, was floating on his back with his PFD keeping his head out of the water, when he decided to join his mom, who was walking along the marina in parallel with the kids and keeping an eye on them. As he swam toward his mom, he was electrocuted by the AC voltage gradient in the fresh water. Mom saw that her son was in trouble and leaped in the save him, as suffered electric shock herself, but fortunately did not drown. Dad came rushing to the scene, too late. He suspected that it wasn't a simple drowning, researched the matter, and changed careers to become a teacher of ABYC standards and promoting changes to those standards to prevent future so-called electro-shock drownings (ESDs), some of which, like his son's are not drowning at all, but electrocutions. See this link for the story: http://www.huffingtonpost.com/terry-gardner/esd-hidden-danger-in-fres_b_693454.html I recently heard the dad, Kevin Ritz, tell the tale at a seminar he gave at the marina where my boat is being refurbished, and I had read about the story earlier in the local boating press. So I ordered an ELCI (Equipment Leakage Circuit Interrupter) with an automatic disconnect relay to cut both the hot and neutral leads coming from the shore power inlet on my boat in case of either a fault current being detected flowing through the neutral lead from the shore power cord or in case of reverse polarity (white wire hot, black wire neutral). And I added an isolation transformer, too. All these things led me to trust in the ABYC standards rather than the K3 Owner's Manual in deciding how to wire the DC power cable that leads to my K3. And led me to pose the question that started this thread. Jim K7KK -- K3 #5263 Remember, Ignorance is the Mother of Adventure! -- Hagar the Horrible In 2011-04-03 12:20 PM, W8JH wrote: Sadly enough we had a local man in his early 20's who was killed by ESD when he dove in to retrieve a pair of glasses a woman had dropped off the dock. This was in fresh water (Lake Erie) at South Bass island. A bit OT for sure but I do think about that when in a marina with power. Joe, W8JH, K3 1713 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] [K3] Why fuse the negative lead from a battery?
I'm a new K3 owner, and I chose the K3 in part because of its small size, because I intend to install it in my boat, which is already cramped for space. I am re-wiring the boat to comply with ABYC (American Boat Yacht Council) standard E-11, /AC and DC Electrical Systems on Boats/. I have a conventional negative-ground DC system. The ABYC E-11 standard requires that in such a system, overcurrent protection (fuse or circuit breaker) to protect the boat's wiring shall be in the ungrounded (positive, red) conductor and that the grounded (negative, black or yellow) conductors in branch circuits (such as the one that one powers my ham station) shall /not/ have fuse or circuit breakers in them. The /K3 Owner's Manual/, however, states (under Specifications, on page 8) that [w]hen a battery is used, both sides of the battery cable should be protected by fast-blow fuses. I wonder why the manual recommends that the negative lead should be fused? Can anyone explain this for me? I intend to wire the K3 power lead with fast-blow fuse in the positive (red) conductor only, in compliance with the ABYC E-11 standard. But ,still, I wonder: why does the K3 manual recommend fuses in /both /conductors: the black (grounded, -12V) as well as the red (ungrounded, +12V)? Jim Maynard, K7KK __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [K3] Why fuse the negative lead from a battery?
On 2011-04-02 01:03 AM, Dave, G4AON wrote: With car electrics (and a boat may be similar), the reason is that if the engine grounding strap fails (or is removed and not replaced), the starter motor can draw current via the radio negative lead which leads to damage and possibly fire. 73 Dave, G4AON Thank you, Dave, your answer reassures me. In fact, boats are quite different from cars. In cars, it is common to use the chassis as a common ground return. In boats, this is forbidden. To avoid ground loops, the various types of grounds on a boat (the DC safety ground [green], the AC safety ground [green or green with yellow stripe], the lightning ground terminal, the bonding ground for prevention of electrolysis, the RF radio ground, etc.) have only one common point, which is usually the engine negative terminal. In boats, only the starter motor is connected directly to the engine negative terminal. Other DC circuits on a boat have three (3) wires: the ungrounded normally current-carrying conductor (red, DC+), the grounded current-carrying conductor (black or yellow, DC-) and the grounding conductor which normally does not carry current (safety ground, green or bare wire). Similarly for AC circuits: the ungrounded normally current-carrying conductor (in the USA, black, in the EU, brown), the ungrounded current-carrying conductor (in the USA, white, in the EU, light blue), and grounding conductor that normally does not carry current (in the USA green, in the EU, green with yellow stripe). Both the DC and AC safety grounds have only one common point: the engine negative terminal. Other circuits, such as the ham radio circuits, are on the other side of a main circuit breaker which cuts both the DC+ (red wire) and the DC- (black or yellow wire). Likewise, AC branch circuits are on the other side of a main circuit breaker which cuts both the hot conductor (ungrounded, black in US, brown in EU) and the neutral conductor (grounded, white in US, light blue in EU). The safety ground (green with yellow stripe) is never switched. So in the scenario that you describe, if the engine grounding strap should fail or be removed, my boat's main DC circuit breaker will trip, disconnecting both the DC- (black or yellow) and DC+ (red) conductors but leaving the grounding safety ground (green wire) connected to the safety ground bus. The branch circuits downstream of the DC main circuit breaker then have fuses or circuit breakers only in the ungrounded (red) conductors. Thank you, Dave; your explanation reassures me - because I know how boat wiring differs from automobile wiring. 73, Jim, K7KK __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [K3] Why fuse the negative lead from a battery?
Right, Bob. What you say is true of AC residential wiring. Boats are different. The so-called main AC breaker on a correctly wired boat breaks both the hot wire(s) -- black or in 120/240 VAC single phase, black and red) and the neutral (white) wire -- coming from the boat's shore power inlet. Also, boats are required (by ABYC E-11) to have a reverse polarity indicator or alarm to alert the user if he plugs his shore power cable into an incorrectly wired shore power pedestal outlet at the marina. The marina's shore power outlet at the pedestal near your slip is, from the point of view of the requirements for residential or factory wiring, a BRANCH outlet, and one in a particularly damp and hazardous location, where a Ground Fault Circuit Interrupter would be appropriate. (Most marinas lack GFCIs however.) The shore power coming on board a boat at its shore power inlet has its neutral and safety ground conductors tied together only at the main power inlet for the whole marina. At the shore power pedestal at your slip, there is usually a noticeable different in AC voltage between the neutral and safety ground. (If indeed, there *is* a safety ground -- too often marinas are wired incorrectly!) This can be a particular hazard in marinas in fresh water. If there were a wiring fault aboard your boat - or a nearby boat - there can be an AC potential gradient in the fresh water surrounding the boats, and anyone swimming nearby can be electrocuted by that AC voltage gradient. (People are more conductive than fresh water, but less conductive than salt water. So-called ESD -- electro-shock drowning -- can and does occur.) So I am wiring my boat acccording to the current ABYC E-11 standard rather than according to the National Electric Code that applies to residential wiring. I am installing ELCIs (Equipment Leakage Circuit Interrupters) for each shore power inlet, and I am also installing an isolation transformer, wired according to E-11, with the case connected to the boatside ground, and the shield between the windings connected to the shoreside neutral (white wire coming from the marina's shoreside pedestal). You are correct, Bob, in describing residential wiring. But boats are different! Jim Maynard, K7KK At 2011-04-02 05:14 AM (Pacif Daylight Savings Time), Bob Naumann wrote: Jim, You said: Likewise, AC branch circuits are on the other side of a main circuit breaker which cuts both the hot conductor (ungrounded, black in US, brown in EU) and the neutral conductor (grounded, white in US, light blue in EU). The safety ground (green with yellow stripe) is never switched. The neutral or white wire in USA residential wiring is never cut by a circuit breaker. Both neutral and protective ground circuits are continuous and tie together only in the main circuit breaker panel (typically) and neither are cut by a circuit breaker. In the case of normal residential 120/240v single phase circuit panels, both hot wires are indeed broken by a Main 2-pole circuit breaker. 240v branch circuits (2 hots) also use 2-pole breakers. In 120v branch circuits, only the single hot wire(black) is cut by a circuit breaker. 73, Bob W5OV (retired electrician) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
