Re: [Elecraft] SB-244 Right to Repair Act

I don't have a K4 nor am I likely to afford one any time soon. I am curious to learn more of its internal hardware architecture, which I can infer from professional experience, but the many discussions on the K4 groups.io forum have made clear that the 'secret sauce' is largely in the software/

[Elecraft] OT: regulation quality of Astron SS-25 power supply?

I've been using the SS-25 as the supply for my K3 or K2/100 for several years. I've been curious about how much voltage drop I see in the stock DC power cable that came with the K3 as a function of supply current. No DC power distribution blocks here - just straight cable from K3 PowerPoles to

Re: [Elecraft] K3 not making power

Hi Jim, Is the low TX power present on all bands? Even though it may be fruitless, try the TX Gain calibration routine using the K3 Utility and a good dummy load. If you're doing the TX Gain cal manually, be sure to set the internal ATU (KAT3/3A) in 'BYPASS' before doing the calibration. The pr

Re: [Elecraft] K2 Keypad

Hi again, Bill, I re-read your post and realized that it's only the buttons to the right side of the LCD display that fail to function (with the exception of the MODE button). Is that correct? If so, I will retract my statement about the parallel load shift register not working properly. If it w

Re: [Elecraft] K2 Keypad

Hi Bill, I think you've got a genuine hardware problem rather than being transported into an unknown menu setting. Does the MENU button work at all? Can you change the frequency display by rotating the main tuning knob? The K2 uses a parallel switch status polling process to determine the switc

Re: [Elecraft] P3 troubleshooting. Does not power on

Hi Cory, I opened my P3 this morning to look at the rear panel I/O board. The fuse I mentioned is an SMD flat pack, so likely a resettable poly fuse rather than a conventional wire fuse. Not designed for quick replacement by the operator. If you hold the front panel POWER switch, do you see any

Re: [Elecraft] P3 troubleshooting. Does not power on

Hi Corky, There is an internal 1 A fuse on the rear panel I/O board. If the fuse is intact, more diagnostics are required. 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailma

Re: [Elecraft] P3 troubleshooting. Does not power on

Hi Tom, Do you have either or both of the SVGA or TXMON boards installed in your P3? How is the Power jumper block configured (e.g. P3 powers up automatically whenever +12V is present at the rear jack, or only with the front panel power switch activation)? The very low 3.3V bus voltage suggests

Re: [Elecraft] KPA100 U1 Voltage a liitle Bit low

Hi Holger, Measure the voltage at the output terminal of U3, the +5V regulator that supplies U1's V_DD voltage. If that is also 4.833 V DC, then all is OK. Due to component variations, one can expect to measure DC voltages within 10% of the nominal table values. Your reading, depending on which

Re: [Elecraft] K2 options

Hi Ron, I've not seen any 'dimensioned PCB' layouts for the K2 RF board or Control board. The manuals over the years have included the skeleton drawings of parts placement, but no scale is included. I suppose if someone had a K2 RF board which is bare and could take a photograph of it, one could

Re: [Elecraft] K3s problem

Hi Curt, Do you have the internal ATU in your K3s? If so, disable it by putting it in Bypass mode and repeat your experiment. Does the Forward power meter show any output power, and can you confirm the actual output power with an external power meter? If you still have a very high SWR into a du

Re: [Elecraft] K1

Hi Mike, Can you verify if the correct coils were installed on the filter board in the Band 1 and Band 2 positions? Same question for the two crystals used in the PreMix oscillator? 73, Mike, K8CN __ Elecraft mailing list Home: http://ma

Re: [Elecraft] KPA100W amp and KAT100 Tuner for the K2 in an EC2 Enclosure

Hi Ray, I don't have a copy of Lyle's original document. One alternative description of the integration of the KPA100 with the KAT100 in an EC2 enclosure is here: https://ke4rg.blogspot.com/2015/03/assembling-and-using-kpa100kat100-ec2.html I did this integration in 2018 with a KPA100 I built an

Re: [Elecraft] K3S PART ID

I checked the interior of my K3 with the new KPA3A 100 watt PA module installed. There is an L-shaped hold-down bracket on the rear edge of the KPA3A board, which is secured to the rear fan panel with a single screw (not visible from the top opening of the case). It matches the dimensions of the br

Re: [Elecraft] K3S PART ID

Hi Mike (K4PI), I recall a bracket like the one you described from my recent addition of the KPA3A 100 watt PA module to my much older K3/10. I don't find mention of it in the KPA3A manual, but my recollection is that it was installed on the rear panel of the K3 to stabilize/hold down the KPA3A mo

Re: [Elecraft] Band-specific low output

Hi Roger, The fact that the low output corrected itself after a band change suggests a relay problem in either the lowpass or bandpass filter sections. Have you tried to run a TX Gain Cal routine lately? If not, that would be a worthwhile first step before opening the case and poking at relays.

Re: [Elecraft] k2 q6 no 12v on q6 collector,

Hi Carlos, Since there is zero voltage measured on either terminal 1 or 2 of transformer T2, I would look at RFC4 and test continuity there. It could be that RFC4 is now open. Keep tracing the voltage along that +12V rail back to the point where it supplies the Q7 and Q8 collectors via the transf

Re: [Elecraft] k2 driver q6

Hi Carlos, When you say 'no voltage' measured on Q6, can you be more precise? The collector of Q6 should measure about 12 V DC whether in TX or RX. The base and emitter voltages will be zero until the transmitter is keyed on. The base voltage depends on the selected mode (CW or SSB), and I reco

Re: [Elecraft] (ot) noise reduction resources

Hi Robert, You've used the term 'receiver noise', but specifically mentioned heterodynes and harmonics as being of concern. All receivers, Elecraft not excluded, have internal spurious signals generated in the VFO and BFO circuits as well as clocks for digital circuits in the radio. The best way

Re: [Elecraft] K2/100 down power on 20M

Hi Jerry, I agree that the relatively low TX power output on 20M originates in the KPA100 module. Did you build that module and install it yourself? The LPA circuit in the base K2 seems to operating normally, and your peaking of the BPF confirms that. If you have capability to sweep the 20M/30M

Re: [Elecraft] Considering purchase of K4D

Hi Allen, If you're not already aware of it, there is a dedicated K4 forum on groups.io that is likely a richer source of answers to your question. The posts here regarding the K4 are infrequent. Be prepared for a fire hose of response when you pose your questions over there - elecraft...@groups

Re: [Elecraft] K2/100 refurbishment

Hi Steve, No answer for your question #2 - Elecraft sells packs of 25 screws for modest price, but shipping to U.K. and VAT (if applicable) may dictate otherwise. Maybe pose that question to John, G3PQA - he's done a lot of work on Elecraft radios for fellow hams in the U.K. Before doing any tes

Re: [Elecraft] K2 Number

Hi Harold, The K2 serial number is on an adhesive tag to be placed on the lower rear panel of the radio. It was in a very small manila envelope in my K2 kit. I don't believe there is any internal coding of the MCU that contains the rig's serial number as there is in the K3. 73, Mike, K8CN ___

Re: [Elecraft] Configure to send CW in SSB mode?

Hi Mike, >From K3 Owner's Manual in the section describing menu entries, p.55: CW WGHT 1.15 Adjusts element/space timing ratio (weight) for the internal keyer. Additional functions of this menu entry, via numeric keypad (Advanced): Tap 1 to select SSB -CW (default) or SSB +CW (allows CW in SSB mo

Re: [Elecraft] K3/100 TX problem on 20m

Hi Paul, I'd say that our respective KPA3A TX Gain calibration values are similar enough. Having not had the bipolar PA model KPA3, I don't have a point of reference for whether your TX gain parameter values are reasonable or not. I would contact Elecraft Support and copy Keith, WE6R with a req

Re: [Elecraft] K3/100 TX problem on 20m

Hi Paul, For comparison, here are the 50 watt TX gain values from the calibration I did last November when I installed the KPA3A 100 watt PA in my K3 (s/n 67xx): 1900 kHz TXGain HP 10 3750 kHz TXGain HP 06 5336 kHz TXGain HP 08 7150 kHz TXGain HP 08 10125 kHz TXGain HP 08 14200 kHz TXGain HP

Re: [Elecraft] K3/100 TX problem on 20m

one of the filters (either BPF or LPF) and the associated relays that select the filters. 73, Mike, K8CN From: dyno lab Sent: Tuesday, March 5, 2024 11:19 AM To: Michael Carter ; Michael Carter via Elecraft Subject: Re: [Elecraft] K3/100 TX problem on 20m [You d

Re: [Elecraft] K3/100 TX problem on 20m

Hi Paul, Could you please post the TX gain parameters recorded by the K3 Utility at the 50 watt level for all bands? If there is a significant difference in those gain parameter values between adjacent bands (say 30 and 17 meters) and the value on the 20 meter band, that may be an additional clue

Re: [Elecraft] PCB Cleaning - followup

Hi Harold, It's certainly true that cold solder joints can arise from dirty/corroded PCB solder lands. The Elecraft boards in my K2/10 (now 17 years old, built by me) are very good quality with plated-through holes and durable solder mask. I had occasion to open my K2 to install the SSB and nois

[Elecraft] K2 troubleshooting (was: K2 AGC)

Hi Iran, I changed the subject line to reflect that this thread is continuing as a general troubleshooting exercise with your K2. The NE602 product detector has a balanced output circuit and unless you use a differential scope probe (or do the CH1 - CH2 trick with your single-ended probes) you wi

Re: [Elecraft] K2 'CAL TPA' setting maxed out

Hi Jim, I don't have an answer to your question, but will note that you are the 2nd person in the last month to report this issue. Thomas, WA8UNS also experienced repeated random resettings of the CAL TPA parameter to large values, often in excess of 200. He reset the parameter to the actual room

Re: [Elecraft] My K3S Has Issues- Ideas?

And one more thought, with thanks to Bill, K9HZ who reminded me that relay K1 on the KPAIO3A riser board can produce the same symptoms if it fails to engage the 100 watt PA module when the Transmit Power control is set above 12 watts. 73, Mike, K8CN

Re: [Elecraft] My K3S Has Issues- Ideas?

Hi Dick, Does your K3S receive OK if the TX Power control is set to less than 12 watts? Do you have transmitter output if the TX Power control is set to less than 12 watts? If the answer to both of those questions is 'Yes,' then you're looking at one or more of the following issues in the KPA3A

Re: [Elecraft] K3 Sub-RX Deaf on One Band

I'm glad that one was relatively easy to resolve, Pete. No hardware intervention required - sigh of relief. Joe is a wealth of knowledge! 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help:

Re: [Elecraft] K3 Sub-RX Deaf on One Band

Hi Pete, If you've confirmed that the RX ANT is NOT selected on the 80 meter band for the sub-RX, I would check the CONFIG entry for the KRX3 to be sure that it's not selecting the AUX RF input. It might have been selected inadvertently if you used BSET to change the sub-RX settings. 73, Mike,

Re: [Elecraft] K2 TUNE power reduction without ATU installed .

My apologies to Steve and Dave W8FGU! I re-read the KPA100 manual and learned that the K2/100 DOES reduce TX power to 20 watts when the TUNE button is pressed and the POWER control setting is above that level. I have my KPA100 integrated with a KAT100 in an outboard case rather than being install

Re: [Elecraft] K2 TUNE power reduction without ATU installed .

Hi Steve, There is no documented method to set a lower TUNE power when a non-Elecraft external ATU is used or when no external matching unit is present. The TUNE button on the K2 keys the transmitter at the requested TX power set by the POWER control, e.g. 100 watts, in the absence of a connected

Re: [Elecraft] K3S audio issue?

Hi Dave, By 'full output' do you mean on transmit or receive or both? The SSB filters are physically the same for USB or LSB on a given filter slot.What differs is the frequency offset programmed into the TX DSP. Check the procedure on p. 49 of the K3S Owner's Manual to see what you have stor

Re: [Elecraft] [Elecraft-K3] K3S TX calibration failure

Hi Ron, Did you use the K3 Utility to run the TX Gain Cal automatically or did you perform the calibration manually? If you used the K3 Utility, it should display the status of the TX Gain on each band and at each of the 3 power levels. Does the TX Gain Cal report indicate that the transverter o

Re: [Elecraft] K2 SSB Power Overshoot on First Syllable

Hi Karin, You've resurrected a topic that was once very active on this same Elecraft reflector: https://www.mail-archive.com/elecraft@mailman.qth.net/msg27397.html It's a long thread. I recommend skipping down if you're in a hurry to read the post by David, M0DHO: https://www.mail-archive.com/

Re: [Elecraft] K3 circuit breaker

Hi Mark, The high current condition on the KPA3 (or KPA3A, if newer K3) PA module may arise from a problem in one of the lowpass filter sections if it's not purely an external fault condition. If you have the internal KAT3 ATU, you could try putting a dummy load on the 2nd antenna port and occ

Re: [Elecraft] Correction, pricing info for k3s/p3

Hi Jerry, When I'm searching for pricing information on used ham gear, I search three sites https://www.eham.net/classifieds https://forums.qrz.com/index.php?forums/ham-radio-gear-for-sale.7/ https://swap.qth.com/index.php Each of these sites enables search for specific keywords. It may take a

Re: [Elecraft] K3 displayed power out is incorrect

Hi Gary, The K3 computes forward and reflected power from samples taken in the SWR bridge circuit. A Tif X Gain calibration could fail because the forward power reading is incorrect due to a failure in that portion of the SWR bridge circuit. Do you have the KAT3 ATU in your K3? If so, be sure tha

Re: [Elecraft] Noise from KAT500?

One more thing to check, Eugene: Are the other two antenna ports on the KAT500 connected to anything? If so, disconnect those ports other than the one you used in your video demonstration. 73, Mike, __ Elecraft mailing list Home: http:/

Re: [Elecraft] Noise from KAT500?

Hi Eugene, Are you using a switch-mode power supply to feed the KAT500? If so, try a linear regulator supply or a battery instead. Is your KAT500 bonded to your other station equipment and AC ground with a short, wide conductor? (not just the coax shields) Since you're not the original construc

Re: [Elecraft] K3 - Erratic receive

+1 for what Brian, K0DTJ suggested! The front panel buttons use a similar voltage divider with a multiplexed A/D converter to determine which button has been depressed. 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net

Re: [Elecraft] K3 KAT3 usage

Hi Paul, Glad the TX Gain calibration fixed the ATU issue. Always thankful for the 'no soldering/de-soldering fixes required!' 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://ma

Re: [Elecraft] K3 KAT3 usage

Hi Paul, I would first check that the KAT3 is still enabled. Use the CONFIG menu to scroll through until you see the KAT3 status. I find sometimes that if my finger lingers too long on the ATU TUNE button, it causes the ATU to go into BYPASS mode, i.e. the ATU is not inline. It should show BYPAS

Re: [Elecraft] K3 low temperature VFO tuning oddity - clicking relay

Email copied below is from a post I made in response to Jim, K9YC on the elecraft...@groups.io forum. This email has some additional observations made early this morning. The shack temperature was a New Hampshire-balmy 54F/12C. 73, Mike, K8CN -- begin copied email --

Re: [Elecraft] K3 low temperature VFO tuning oddity - clicking relay

Hi Pete, I originally posted my observations to both the official Elecraft reflector and the elecraft...@groups.io forum. Until your response on the official reflector there had been only two responses on the other forum. I posted additional observations this morning on the groups.io forum - if y

[Elecraft] K3 low temperature VFO tuning oddity - clicking relay

I've been getting reacquainted with my K3 (S/N 67XX) since adding the 100 watt PA module (KPA3A) last weekend. I also updated the firmware to the latest versions and ran the TX Gain Calibration successfully at all three power levels. The K3/10 had been sitting disconnected from everything since m

Re: [Elecraft] KPA3A and 6 meter TX Gain Calibration

Thanks very much, Dick! 73, Mike, K8CN From: Dick Dievendorff Sent: Thursday, November 9, 2023 9:20 PM To: Michael Carter Cc: Elecraft Reflector Reflector Subject: Re: [Elecraft] KPA3A and 6 meter TX Gain Calibration CAUTION: This email originated from outside

[Elecraft] KPA3A and 6 meter TX Gain Calibration

Last weekend I installed the 100 watt PA module (KPA3A) in my K3/10 (S/N 67xx). I used the K3 Utility to perform the TX Gain Calibration at the 5 watt, 50 watt, and 1 mW levels - all completed successfully. However, when I read the firmware update page I found that one should perform the 6 meter

Re: [Elecraft] K3 Options Last Time Buy Update

Hi Dave, I can't speak to the module you ordered, but I received on 28 October the KPA3A 100 watt upgrade I had ordered back in spring 2021. The effort to ship upgrades is definitely a 'live effort,' and the Shipping Status updates on the Elecraft web page accurately reflected the status of the m

Re: [Elecraft] [RFI] HI CUR warning on K3

Hi Pete, I had a similar set of symptoms with my K3 several years back. Turns out it was not the K3 at all, but a failing filter capacitor in my linear regulated power supply. I had sporadic audio dropouts after transmitting in much the same way as you described, always at QRP TX levels. Try a

Re: [Elecraft] K2 Sidetone help

Thanks to Don, W3FPR for the reminder on how to check the firmware version. To Mike, WA5POK: as point of reference, I checked my K2 STL setting and it's quite loud at 002 using headphones. I recommend trying a lower STL level setting than the 060 I originally suggested. I only use headphones an

Re: [Elecraft] K2 Sidetone help

Hi Mike, You mentioned that you jumped through all the menu hoops to no avail. Do you know which version of firmware 2.04 you have installed? (there will be a letter after the 2.04, e.g. 2.04P or 2.04R). If you have set the sidetone level to, say, 060 and the sidetone pitch to a value between 50

Re: [Elecraft] K3 Randomly Changes Modes

Hi Gary, I bet you've never used that retort before now. I don't need any servants, but I could use a 'memory' (not Memory) with same day service. 73, Mike __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/ele

Re: [Elecraft] K3 Randomly Changes Modes

Hi Randy, If memory serves me correctly, others have reported similar gremlins with seemingly random activation of front panel controls that were not intended. The remedy was (1) check whether your radio has the gold pin connectors on the front panel-to-RF board interface, and (2) carefully clean

Re: [Elecraft] K3 Filters

Hi Dave, Without a saved CONFIG file, I don't think there is a way to retrieve the filter settings directly from the K3. Have you tried examining the filter settings for any information that is stored in a CONFIG file? The K3 Utility permits viewing and editing stored crystal filter settings. Yo

Re: [Elecraft] Main Ant Port Degraded

Hi Mike, I would first reduce the TX power control for a setting less than 10 watts. That will bypass the KPA3 100 watt PA module via the relay K1 on the KPAIO3 board. If that restores your RX background signal level to be comparable to that observed when you put the same antenna on the RX Anten

Re: [Elecraft] AT1 Attenuator

Hi Steve, Each attenuator section is designed to present a 50 ohm input impedance when terminated in 50 ohms. Of course that will change as frequency is increased and inductive effects take greater prominence. At what frequency(ies) did you make your measurements? What were the actual SWR readin

Re: [Elecraft] K2 Band Data

Hi Jerry, I had forgotten about the KRC2, Elecraft's universal band decoder/relay driver unit, so thanks to Jack, W6FB for reminding us. The K2 uses five separate filter sections (both for bandpass and lowpass selection), and these do double duty for adjacent ham bands. From my brief inspection

Re: [Elecraft] K2 Band Data

Hi Jerry, There is no simple access to band data in the K2 unless you want to reverse engineer the AUXBUS protocol. Depending on how your homebrew amp selects its lowpass filter options, you may be able to pick up the relay control signals for the K2's bandpass and lowpass filter banks and use th

Re: [Elecraft] K3 subreceiver works on CW only

Hi Erik, Did you check the filter selection for the sub-receiver to be sure you don't have a blank slot selected for SSB? 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman

Re: [Elecraft] KPA100 Power Surge Advice

Thanks, Geert Jan, for recounting the 'origin story' of the K2 'twins', the outboard combination of the KPA100 and KAT100. I had not previously heard of the origin and Lyle's (KK7P) role in that process. I hope Larry can provide more detail about the actual configuration of his outboard KPA100.

Re: [Elecraft] KPA100 Power Surge Advice

Hi Larry, You mention in the title '...Power Surge Advice.' I presume your KPA100 was working properly prior to not powering up? You also describe the connection from your power supply to the KPA100 and then to the K2 - does this imply a Y-connection from the power supply to both the K2 and KPA10

Re: [Elecraft] K3 Options Last Time Buy Update and other products status:

Thanks very much, Eric, for the comprehensive update! 73, Mike, K8CN (especially glad to know about the KPA3A being close to shipping) __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qt

Re: [Elecraft] K1 Low power output on one band

Hi Paul, It does sound as though the slug-tuned inductors on the 20 meter and 15 meter sections of the Filter board need tweaking. As you noted, one must remove the KAT1 ATU board from the Filter board to access those coils. It is necessary to jumper pins 2 and 10 of J2 on the Filter board to ro

Re: [Elecraft] K3 Receive gone

Hi Jim, Does your K3 have the KXV3 interface or KRX3 subreceiver options installed? If so, I would check the menu settings to be sure that the rig doesn't have the RX antenna port selected as its antenna source and that the subreceiver isn't the primary receiver. If it's not a menu setting issue,

Re: [Elecraft] K2/10

Hi Allan, In your original post you said your K2 seemed somewhat 'deaf.' Does that mean you hear no signals at all on any band, no signals on one or two bands, or just weak audio with antenna or signal generator input? Since your K2 has the K160RX option, I would check that the RX antenna is not

Re: [Elecraft] When/where was recent officialupdate (from WA6HHQ?) on K3 option last time buy ship status?

Eric posted to this forum in early March 2023. I believe his estimates of availability for various modules are reflected in the current Shipping Status information on the Elecraft web page. Suffice to say that only a few module types have shipped at this juncture. Some of his estimates were in re

Re: [Elecraft] KPA3 Rev B not output

Hi George, Congratulations on your excellent sleuthing! Regardless of which solder joints were reflowed to solve the problem, you found the troublesome one(s). Thanks, too, for reporting back to the reflector - it helps to spread the knowledge base. 73, Mike, K8CN ___

Re: [Elecraft] Starting to Ship K3 & K3S Option Last Time Buy Orders (3/1/23)

Just curious if there is a new update coming out this week since it has been 3 months since the last update (presuming I didn't miss an update and understanding that Elecraft has been traveling to various ham conventions)? 73, Mike, K8CN

Re: [Elecraft] Power spike early K3

Hi Mike, I saw that you had posted a similar question in January 2023 and had some suggestions including running the TX Gain calibration, which you did, but apparently without effect on the spiking. There have been numerous reports of TX power spikes on first dit or first voice sound. Some found

Re: [Elecraft] K3 RX Issue?

Hi Lee, Do you also have a reduced RX signal level on 30 meters as well as 20 meters, at least by comparison with your KX3? Since the TX output is OK, I will hazard a guess that one of the relays in the 20/30M bandpass filter is not making good contact or has developed a weak solder joint on the

Re: [Elecraft] K3S dead.

Hi OM, I would first disconnect anything connected to the rear panel ACC connector - pin 8 may inhibit the PWR_ON signal. If nothing is connected to the ACC jack, I would try temporarily grounding the end of R77 (the other end attaches to pin 4 of Q2), which is the /PWR_ON signal. If that fails

Re: [Elecraft] K3s problem

Hi Jerry, First, a couple of questions: -- does the abrupt loss of power occur if you operate with the TX PWR set to less than 12 watts on 15 meters? This engages only the low power driver amplifier and takes the 100 watt PA module out of the picture. -- if you're operating on 15 meters at the

Re: [Elecraft] K3 Won't Turn On all of a sudden!

Hi Rick, I've not experienced the problem you described, but I've also not used my K3 as a remote front panel for another K3. Have you checked pin 8 of the ACC connector to be sure that it is not held 'high' by some chance (not likely since you pulled all the cables)? If there isn't a problem wi

Re: [Elecraft] K3 KPA100 not putting out in high power

Hi Jim, Since the bypass relay actuates, can you check the KPA3 (or KPA3A, depending on which generation of K3 you have) input side of the relay to verify that the relay is doing its job, i.e. that RF is making it onto the KPA3 input? A scope is best, but a simple RF probe and DMM would also suff

Re: [Elecraft] Keying the K3s

My previous post under this thread elicited a private response from Kent, K9ZTV who noted the same concern expressed by others publicly about using the TUNE button with the PWR control set ** exactly ** at 5.0 W or 50 W. I thank Kent for piquing my curiosity about this issue because I had not expe

Re: [Elecraft] K3S-KPA3 100 Watt Amplifier not working

Hi Dick, By 'not working' I presume you mean that advancing the TX Power control above 12 watts does not yield increasing TX power output? Does advancing the TX Power control above 12 watts produce any increased TX output power or none at all? Here I presume you have an external wattmeter with w

Re: [Elecraft] Keying the K3s

Hi Dave, The K3s (and K3) bypasses the 100 watt PA module when you set the Power control to less than 11 watts and relies on the KLPA3A 10 watt PA driver module. No harm will come to the K3s when operating at 5 watts presuming you have an SWR within spec for the K3s. I used a simple optocoupler i

Re: [Elecraft] K2

Hi Mark, It sounds like self-induced RFI, but occurrence at a very low nominal TX power is suspicious. Can you say more about: -- antenna(s) in use -- any external or internal ATU in use -- connections to your K2 other than antenna, DC power, and key/paddle? 73, Mike, K8CN __

Re: [Elecraft] K3 - 100 watt amp dead?

Thanks for the update on your visual inspections, George. Best wishes for the holidays! 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:El

Re: [Elecraft] 12 v power source for Elecraft Transceivers

"Clearly case of stimulation of overactive ham hormone resisting disposal of anything looking potentially useful." Ed, your characterization of this personality quirk is the best explanation I've seen yet - I'll share it with my XYL, although I doubt it will temper her (un)enthusiasm for my collec

Re: [Elecraft] K3 - 100 watt amp dead?

Hi George, Your test confirmed that the low-power amp (K3 LPA) survives. To clarify, do you have the K3 or K3s? The original 100 watt PA (KPA3) used RF BJTs as the finals, whereas the KPA3A used RF MOSFETs (LDMOS). Apart from failure of one of the PA final transistors, the loss of TX output powe

Re: [Elecraft] K3 #8862 unwanted sidebands

Thanks, Wes! As a 99.9% CW operator, I never looked into the Tech Mode options for SSB testing in my K3. That's a really useful feature! It's good to be reminded of the built-in troubleshooting utilities in the K3. 73, Mike, K8CN

Re: [Elecraft] K3 #8862 unwanted sidebands

Hi Martin, Do you observe (or hear) sidebands outside the nominal transmitted bandwidth with CW transmissions or only SSB transmissions? Can you perform a 2-tone test with an audio source other than speech? The fact that the unwanted sidebands are not observed when the KPA3 100 watt amplifier is

Re: [Elecraft] [K3] Strange Selective Hearing in My K3

Hi Eric, I'm voting with my friend Dave, K1WHS, for looking first at the voltage regulators. The 8 volt regulator supplies the TC4427 gate driver IC, which in turn provides 7R/7T voltages separately to the Transmit and Receive switching circuits. The loss of the 7R/7T voltages would disable the P

Re: [Elecraft] K2 Question: RF Gain Pot

Hi Dave, You'll need to replace that pot. I've got the same problem in my K2/10, and it's getting progressively worse. The issue is not solvable with contact cleaner - I recall older posts on this same problem, and the advice was the same: replace the pot. Some commenters suggested ordering rep

Re: [Elecraft] K2 Menu Button

Hi Aaron, The symptoms you describe indicate to me a mechanical flexure problem. I would pull the Front Panel board out of the RF board socket (first removing the Control board) and carefully inspect all pins for corrosion. I would also inspect the solder joints on the Menu/Edit button switch.

Re: [Elecraft] problem with K2, KAT100 and K2100PA combo

Occam's Razor comes to mind - forget all that diagnostic stuff I pumped out earlier! Glad you found the true cause, the simple true cause, Brian. 73, Mike, K8CN __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecr

Re: [Elecraft] problem with K2, KAT100 and K2100PA combo

Hi Brian, Could you give a bit more detail? You said the 'power went off on the K2' after attempting to auto-tune the KAT100. Do you mean the DC power went dark on the K2 and the screen display went blank, or something else? Have you tried to auto-tune the KAT100 at the low power level (set K2

Re: [Elecraft] k3 no power out over 12 watts

Hi Scott, Check the KPA3 settings in the CONFIG menu to be sure the 100 watt PA is not bypassed. If the KPA3 is set to PA NOR in the CONFIG menu, then you may have a diode failure in the PIN diode T/R switch or the PA bypass PIN diode switch. Mike, K8CN

Re: [Elecraft] Indefinite support for K3s

Wayne, N6KR, posted on 23 April that Eric (WA6HHQ) will have an update on K3 modules 'next week.' My recollection is that Elecraft set a cutoff date in spring 2021 for ordering of K3/K3s modules to gauge interest and allow ordering of long-lead-time parts. I can't find another recent post in whic

Re: [Elecraft] K2 SN 25xx has very low sensitivity in 20 and 80m bands

Hi Chris, Does your K2 transmit OK on those bands, i.e. at full power output? The fact that other bands have normal sensitivity indicates that the main receiver functional blocks are OK. The bandpass filters for 20 and 80 meters have only one component in common, relay K3, but that relay selects

Re: [Elecraft] question order date of recently received K4D

Hi Darrell, Join this group to get a good handle on delivery rates of K4/K4D radios: creativek4shippingsta...@groups.io It's a lot of fun to watch the delivery reports and serial numbers roll in! 73, Mike, K8CN __ Elecraft mailing list

Re: [Elecraft] Interference on 17M

William, I suspect you had an attachment stripped by the reflector. Was it a sound file or spectrum view? Ron, does the RFI occur only on 17M? I presume you've checked other bands? The switch-mode power conversion in PV inverters can generate RFI across a broad spectrum, but it would be unusual

Re: [Elecraft] KPA500 Mosfet SD2933 vs VRF2933

Hi Ziv, The SD2933 is an older part - Mouser lists it as 'obsolete' and otherwise unavailable. A review of the datasheets for the two devices (VRF2933, SD2933) reveals that the VRF2933 has a higher drain-source breakdown voltage than the SD2933, and it is tolerant of SWR values up to 70:1. The S

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