[Elecraft] "Real" CW
Cool video, This video reminds me of some of the equipment that I used to work on in the late 1970's. I used to work for ITT Mackay Marine. I was not a radio operator. I worked as a bench technician repairing HF receivers and other equipment that were removed from the ship for service. 73, Bob Johansen WB2SRF Get the shot you need with a discreet new spy camera. Click now! http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m1ErIN8t8bondJL4F3LxQ5xJvR5klFdqW1ab4KhbCg9SloO/ ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 troubles
>From the symptoms, I suspect that there is a bad connection somewhere. Perhaps some pins are not soldered under the microprocessors IC socket. You may wish to check some archives on this reflector that address this particular problem. Microprocessor IC's are pretty reliable provided that there was no high voltage stray static electric charges present when the chip was removed from the packaging. This is a big problem when the air is very dry and if there is a tendency in the room for sparks to fly when walking across a carpet and touching a doorknob etc.It is always a good idea to follow ESD safe procedures to guard against possible damage to semiconductor devices. GL 73, Bob Johansen WB2SRF K2 S/N 5622 Staten Island, NY 10302 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Out Board PA
>From what I recall, the I/O cable needs to be attached between the K2 and KPA100 before the PA menu changes. GL 73, Bob Johansen WB2SRF SI, NY K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 100 Watt Pa Problem
>From the description of your problem it could be your power supply. Check the power supply voltage with a analog or digital voltmeter, under load it should not drop below 12V. The K2/ KPA100 requires a good high current power supply. I use an Alinco DM-330MV set to 13.8V. This power supply is rated for an output current of up to 32 Amperes. GL 73, Bob Johansen WB2SRF K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] MH2 Mic replacement cord
Very disappointed in the mic cord. Poor QC in my opinion I was going to send it back to Elecraft, but decided to replace the cord with a very flexible thin rubber coiled cord removed from a spare $5 cheap dynamic CB microphone Workman electronics "Super Star" DM-507-4. The "Superstar" is not a bad microphone for use with the K2, but does not have as much microphone gain as the electret in the MH2. Made several DX contacts with it so it seemed to have enough punch in the audio. What can I say, I guess it was a (expensive) psychological need for me to get a matching Elecraft microphone to complete the rig. I also have another "Superstar" microphone wired up for the K2 so that I can do some A/B tests. I installed a 5.6K 1/8W resistor inside of the MH2 mic plug so that the bias voltage is removed when this mic is disconnected so that I can plug in and use the dynamic microphone. 73, Bob Johansen K2 SN 5622 Staten Island, NY USA ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Splicing mic cables
I remember having the same problem when I worked as a technician in a two-way radio repair shop in the 1970's. Some Motorola microphone cables were made with tinsel wire and required an IDC (insulation displacement crimp) connector lug. It was a small solder lug with teeth on one end that bit through the insulation when crimped over the wire. Motorola had a parts kit available. I am not sure if anything like this is still available. You may try stripping the tinsel wire a use a common small crimp on wire terminal to make a connection. GL 73, Bob Johansen WB2SRF Staten Island, NY K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 noise blanker
When I first completed the K2 with the noise blanker option and ran some tests, I also expected to hear more of a difference in backround noise reduction. Unless it is repetitive pulse noise the blanker has no audible effect which is good in some respects compared to other receivers like the Icom 706 noise blanker which can needlessly distort the reception of strong signals. The blanker is very effective in eliminating lamp dimmer noise, and once I heard the difference it put my mind to rest that the circut which I assembled was working properly. GL 73, Bob Johansen WB2SRF Staten Island, NY USA K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 Noise blanker- is it working?
The best way I have used to test the effectiveness of noise blanker is try to use the radio in a house with a common incandescent lamp dimmer nearby the antenna connection. Use a wire antenna placed near the lamp or wiring of the dimmer circuit if necessary to increase the coupled noise. The power line frequency zero crossing pulse width modulator (severe contant buzzing sound) of the lamp dimmer noise will be almost completely supressed if the noise blanker circuit is working properly GL 73, Bob Johansen WB2SRF K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2/100 or K3/10?
I built the K2 with internal battery and all accessories for a compact stand alone QRP rig and the KPA100/ KAT100 in a separate EC2 enclosure for QRO base operation. Enjoyed assembling the kits, lots of toroid winding and soldering. I find that I use the K2 QRP the most when spending time outdoors. CW and SSB Have other rigs for the base operation including a Icom 701, Icom 706, mil spec Sunair GSB-900 with auto antenna tuner (good for SSB) so have not used the KPA100/KAT100 that often Am not into contesting so do not see a need for an upgrade at this time. With all of the recent talk about the importance of Roofing filters, a very good crystal filter right after the mixer is inherent in the K2 design. 73, Bob Johansen WB2SRF K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Looking for static dissipative bench pad
Using a conductor for a ESD ground pad is not a good idea. Besides the obvious short circuit or electric shock hazard that could occur. I learned from taking ESD courses at Lucent Technology and Motorola where I was employed. that slow gradient discharge of the static electric buildup is required otherwise a high peak current can destroy semiconductors. That is why it is called (ESD) electrostatic dissipative A properly designed ESD pad is essentially non-conductive at low voltages because it has well over 1 MegOhm per square Centimeter of resistance. The wrist bands have a 1 Megohm series resistance to allow a path to ground and provide some safety to protect againest electric shock. 73, Bob Johansen WB2SRF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Elecraft news story
Mike, Thank you for posting the article, it was an interesting read. It brought back many fond memories of Heathkit, I built and enjoyed many of their products. Wishing Elecraft's continued success with the K3 and future products. I enjoyed building and now having enjoyment using the K2 and the accessories 73, Bob Johansen WB2SRF K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] BL2 binocular core dimensions
The core size appears the same as the BL-1, The BL-2 uses two identical stacked cores. I just measured my BL-2 so the dimensions are approximately 1.13 ( about 1.5" across depends on how tightly the wires are wound) by 1.12 (0.56x2) high. GL 73, Bob Johansen WB2SRF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] KX1 speaker output with superimposed oscillation
Hi Paco, Great detective work, glad to read that you tamed the beast. Hi Hi I am in the process of trying to model the LM386 circuits using LT spice ( program free from Linear Technologies web site SWCAD III) to try to understand the feedback mechanism that results in these amplifier's becoming unstable and turning into an oscillator. Many times I have had success through trial and error getting circuits to work properly but with the help of some engineer friends, I have been encouraged to try circuit analysis. It is strange that placing a capacitor at the output to ground solved your problem because it can cause a phase shift to result acting with the output resistance internal to the IC. Perhaps the phase shift placed the gain-phase margin outside of the area in a Bode plot to stabilize your amplifier These amplifiers have a problem. Before they run out of gain at high frequencies, if there is 360 degree's of phase shift from input to output of the amplifier it turns into an oscillator. 73, Bob Johansen WB2SRF On Sun, 09 Sep 2007 16:28:43 + "Francisco Barros" <[EMAIL PROTECTED]> writes: > Hi Bob, > > Finally, I got it !. > It is related with "the RC network connected between the output pin > 5 and > ground, required to keep the amplifier stable at high frequencies at > > different loads", as you mention on your previous post. > I checked the RC network and I even installed a new one: same > behavior. > If I removed this RC network completely, the oscillation now started > with > lower volumes !. > > Using the technique "try and error", the problem was solved with a > capacitor > of 68 nF in parallel with this RC network, that is, just from pin 5 > to > ground. No more high frequency oscillation with different loads !. > > By the way, the DC voltage at pin 5 was half the supply: 3 V. I even > > installed a short leads 10 uF tantalum across the supply of U4, > without > positive results. > > I don't know the reason of this behaviour, maybe, as you say on your > post, > is due to the high gain of this stage (46 dB). Who knows... . > > Many thanks Bob and have a good day. > > 73, > Paco > > _ > Descarga gratis la Barra de Herramientas de MSN > http://www.msn.es/usuario/busqueda/barra?XAPID=2031&DI=1055&SU=http%3A//w ww.hotmail.com&HL=LINKTAG1OPENINGTEXT_MSNBH > > > ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] KX1 speaker output with superimposed oscillation
Hi Paco, Sorry to read that it did not work for you. LM386 amplifiers can do strange things when over driven. There is a lot of available gain. If the amplifier is operating properly, the Idle DC voltage with no audio signal on the output pin 5 should be half of the DC voltage measured on the power supply pin 4 if not you may have a leaky coupling capacitor on the input circuit or a bad IC internal circuit throwing off the bias. I have also found at times from building my own equipment that a de coupling capacitor with short leads is needed across the power supply pins 4 and 6 to keep it stable at high output levels especially if the impedance of the power supply is not low enough. I use a 10uF tantalum capacitor when connecting it is very important to observe the correct polarity. Also the RC network connected between the output pin 5 and ground is required to keep the amplifier stable at high frequencies at different loads. GL 73, Bob Johansen WB2SRF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 with internal battery?
I do not think that the Sealed Lead Acid battery used in the K2 will be a problem. The battery manufacturers specifications show that these are pretty rugged unless the terminals are shorted without any outside circuit protection or severly overcharged. 73, Bob Johansen WB2SRF K2 S/N 5622 with internal battery KBT2 and all other options for stand alone QRP Separate KPA100 and KAT100 in EC-2 enclosure for base operation ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Low outout power on higher bands, K2
You may wish to check the power supply current drawn for the maximum output power on each band, If it decreases when you select the higher frequency bands there probably is a RF drive level problem. If the current is high on the higher frequency bands then you have a problem with the output impedance matching filters etc as you stated. How are you measuring the RF output power ? On my K2 with the KAT-2 Bypassed I get only 8W out on 10M @13.8V the KAT-2 has some insertion loss. The lower bands are at least 10W or above 73, Bob Johansen WB2SRF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] KX1 speaker output with superimposed oscillation
Try changing the value of R21 from 2.7K to 4.7K I had a similar problem with load sensitive parasitic oscillation of the LM386 with a Norcal 40 When this happens it can block the receive signal because of the agc action. The (high frequency rolloff) feedback may be causing enough phase shift to cause the amplifier to oscillate. Hope this helps GL 73, Bob Johansen WB2SRF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K3 st TOKYO FAIR
Reminds me when I worked for the Japanese at Panasonic in the late 1980's. We would be handed technical documentation and asked to please correct the english. We called their attempt at english "Jenglish" for Japanese English it was quite a headache at times to understand what was meant to rewrite documents useful for the US market. 73, Bob Johansen WB2SRF K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] any suggestions? cheap qrp xcvr kits
I have a Ten Tec 1340 (4 Watts) and it is a good rig after making several modifications. Add a 10 turn pot for the VFO and Dave K1SWL Frequency Mite audible frequency readout and other simple modifications to improve the transmitter stability and get rid of popping in the received audio during keying all very well documented on the web by Monty N5ESE . Also have a Wilderness Radio NORCAL 40 (2 Watts) which benefits by adding a 10 turn pot and audible frequency readout which costs about $70 more than the the Ten Tec with similar mods. This has a very clean design and is easily upgradable and servicable. It was designed Wayne N6KR one of the founders of Elecraft. There is also a interesting low cost $30 multimode software defined radio kit RXTX 6.2 (1 Watt) that I just completed by Tony KB9YIG but it requires hookup to a PC soundcard with free software. Good luck on making your decision 73, Bob Johansen WB2SRF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 Bandpass Filter Mystery
Hi Beth, Check to make sure that you have the correct band selected. At one time I made the mistake of having the 12M band selected with the VFO tuned to 28 MHz (10M) and experienced the same symptom. GL 73, Bob Johansen WB2SRF K2 S/N 5622 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
