K3 construction problem
Locked
 
|
Since Garry suggested I ask the reflector I am posting the following
that we have been trying to figure out on my K3 kit. Any help would be appreciated Dennis N4ZKR Copies of messages below: Gary Surrency wrote: > OK. Let me know how the testing goes. I don't work on weekends, but > will be back here come Monday morning at 8am MST. > > Someone else in tech support may reply in the interim though, and > there is also the Elecraft reflector you can use as a resource. Use > [hidden email] to be sure more than one person receives your > emails. > > Many times, all that is wrong is there is a bent or misaligned pin, or > a filter setup error. The K3 Utility makes it easy to check the filter > setup, and to test if the serial port and firmware upgrade procedure > works OK. > I have visually checked all of the pins and/or reinserted them > Use care when handling and testing the boards so you do not damage > anything with ESD. The SMT parts are also easy to knock loose from the > PCB, so use care and be gentle. Examine the boards and parts closely > with a bright light and a magnifier to see if there might be some > damage or poorly soldered parts that came loose in handling, shipping, > and during assembly. > EVERYTHING has been done with an ESD wrist strap attached to the radio and on an ESD surface. I dont see anything broken or missing > -- > 73, Gary AB7MY > ========= > [hidden email] > Elecraft Technical Support > > [hidden email] wrote: >> I will check tonight. I am also rounding up a RS232 cable to try the >> K3 Utility tonight also. >> 73 >> Dennis > > >> On Fri Jun 12 12:14 , Gary Surrency <[hidden email]> sent: >> >> >>> When the preamp is turned on, do you hear a slight increase in noise >>> and hiss as it adds its gain into the signal path? No increase with the preamp. No increase in noise when the antenna is connected. >>> >>> A noticeable response in noise should result when you touch pins 1 >>> and 2 of the KR MXR board. Pin 1 is the round pin closer to the P1 >>> label (not the gold plated hole, but the pin next to it). No increase in the noise >>> >>> -- >>> 73, Gary AB7MY >>> ========= >>> [hidden email] >>> Elecraft Technical Support >>> >>> Dennis Wieck wrote: >>> >>>> I did try the test points. The results are listed by each point. I >>>> have rechecked the filter settings. I only have one installed at >>>> present. It is the stock 2.7 in the first position. >>>> >>>> Gary Surrency wrote: >>>> >>>>> Try those test points I mentioned, and be SURE the filter setup is >>>>> correct. The K3 Utility helps a lot to do that. >>>>> >>>>> -- >>>>> 73, Gary AB7MY >>>>> ========= >>>>> [hidden email] >>>>> Elecraft Technical Support Dennis Wieck wrote: >>>>> >>>>>> It is pretty much deaf. There is no increase in noise when you >>>>>> connect >>>>>> an antenna >>>>>> The only filter installed is the standard 2.7 at FL1 >>>>>> I will have to get a cable to do the computer interface. >>>>>> >>>>>> Gary Surrency wrote: >>>>>> >>>>>>> Complete the kit and setup/calibration that you can do, so you >>>>>>> can see if it will transmit. >>>>>>> >>>>>>> >>>>>> It does not show any power out on my wattmeter >>>>>> >>>>>> >>>>>>> Verify VCO CAL works OK. >>>>>>> >>>>>> If this is the synthesizer cal this works right >>>>>> >>>>>>> Look over all boards and connectors closely for correct assembly. >>>>>>> >>>>>>> >>>>>> Checked this >>>>>> >>>>>>> >>>>>>> More: >>>>>>> >>>>>>> >>>>>>> You can try the receiver troubleshooting steps I show below. >>>>>>> This testing is done in the reverse order of normal signal flow, >>>>>>> from the AF to IF to RF circuits. >>>>>>> >>>>>>> You can do this without even having any test equipment. Just use >>>>>>> care to not accidentally short or drop anything inside the rig, >>>>>>> and ground yourself against ESD. >>>>>>> >>>>>>> Try touching these points using an insulated meter test probe >>>>>>> from your VOM or DMM to couple in a little noise to see if the >>>>>>> stages are working. Select a noisy band such as 40m and have the >>>>>>> preamp ON. >>>>>>> >>>>>>> The M1, M2 pads near the far right of the RF board should >>>>>>> produce a click when touched. >>>>>>> >>>>>> This worked >>>>>> >>>>>>> Both of the right hand most pins of the currently selected >>>>>>> crystal filter for the sub should make noise when touched. Make >>>>>>> sure the filter setup is correct. It is easier to see and modify >>>>>>> all of the filter setups in the K3 Utility, under the >>>>>>> Configuration/Edit Crystal Filters button. Incorrect filter >>>>>>> setup is one of the most common errors, as there are lots of >>>>>>> settings to do by mode and by filter position. >>>>>>> >>>>>>> >>>>>> This worked >>>>>> >>>>>> >>>>>>> Pins 1 and 7 of the KNB3 should make a little noise when touched. >>>>>>> >>>>>> Nothing at pin 1 or 7. Removed and reinserted with no change >>>>>> >>>>>> >>>>>>> Check for about the same response for pins 1 and 2 of the KR MXR >>>>>>> and jumper W1 on the RF board just below the KR MXR. This board >>>>>>> is very fragile so handle and test on it with care. >>>>>>> >>>>>> Nothing at KR MXR If W1 is the one labeled IF it does make noise >>>>>> >>>>>>> Also try touching the tiny pin to the side of the trimmer caps >>>>>>> for the band that is currently selected, in the band pass filter >>>>>>> area on the left side of the RF board. >>>>>>> >>>>>>> >>>>>> Nothing >>>>>> >>>>>>> Touching the adjustment screw of the white IF trap trimmer cap >>>>>>> at C218 should produce quite a bit of noise >>>>>>> >>>>>>> >>>>>> Nothing >>>>>> >>>>>>> Many problems are due to having the connector pins not well >>>>>>> aligned and mated on one of the boards. Check for that. >>>>>>> >>>>>> I checked them >>>>>> >>>>>>> If there is no KPA3 installed, either the KPA3 jumper block must >>>>>>> be installed, or the KPAIO3 board with the KPA3 menu set to PAio >>>>>>> ON to bypass the missing KPA3. >>>>>>> >>>>>> It is installed >>>>>> >>>>>>> If there is no KXV3 installed, wire jumpers must be in RF board >>>>>>> connector J66 pins 8-10 and 13-15, behind the KIO3 main board. >>>>>>> >>>>>>> >>>>>>> >>>>>> These are present >>>>>> >>>>>> >>>>>>> -- >>>>>>> 73, Gary AB7MY >>>>>>> ========= >>>>>>> [hidden email] >>>>>>> Elecraft Technical Support Dennis Wieck wrote: >>>>>>> >>>>>>>> I will not be back in town until tomorrow night so I cant check >>>>>>>> until then >>>>>>>> Some answers below >>>>>>>> >>>>>>>> Gary Surrency wrote: >>>>>>>> >>>>>>>>> Dennnis, >>>>>>>>> >>>>>>>>> Does the rig receive or transmit OK? >>>>>>>>> >>>>>>>> I have not tried transmitting. I am at the Ref Cal stage of >>>>>>>> construction >>>>>>>> >>>>>>>>> Can you tune in WWV at 10MHz? >>>>>>>>> >>>>>>>> No. I don't hear anything at any of the WWV frequencies ( or >>>>>>>> anywhere else fo that matter) >>>>>>>> >>>>>>>>> Are all TMP cables in the right connectors, and fully seated? >>>>>>>>> >>>>>>>> I think so but will check when I get home >>>>>>>> >>>>>>>>> Did you verify all of the crystal filter setups are correct? >>>>>>>>> It is easier to see and modify all of the filter setups in the >>>>>>>>> K3 Utility, under the Configuration/Edit Crystal Filters button. >>>>>>>>> >>>>>>>>> >>>>>>>> Yes but I will check again >>>>>>>> >>>>>>>>> REF CAL is currently best done by using Method #2 on page 47 >>>>>>>>> of the Owner's manual. Turn the VFO A knob to adjust, and do >>>>>>>>> not press 1 or 2 on the front panel. First set the VFO readout >>>>>>>>> to exactly 10.0MHz and then adjust the VFO until WWV is at >>>>>>>>> zero beat in both LSB and USB, not CW or data modes. >>>>>>>>> >>>>>>>>> -- >>>>>>>>> 73, Gary AB7MY >>>>>>>>> ========= >>>>>>>>> [hidden email] >>>>>>>>> Elecraft Technical Support Dennis Wieck wrote: >>>>>>>>> >>>>>>>>>> I am at the Reference Oscillator Calibration part of my kit >>>>>>>>>> assembly ( SN 3098). >>>>>>>>>> I am trying to do the method 2 (Zero-Beating) method. The >>>>>>>>>> problem is that I cannot hear any signal to zero-beat to. >>>>>>>>>> Everything up to this point has gone by the book. I loked at >>>>>>>>>> the troubleshooting section but did not find anything that >>>>>>>>>> applied. Power supply voltage is correct. >>>>>>>>>> Can you suggest where to go from here? >>>>>>>>>> >>>>>>>>>> Thanks >>>>>>>>>> >>>>>>>>>> Dennis >>>>>>>>>> N4ZKR >>>>>>>>>> >>>>>>>>> >>>>>>> >>>>> >> >> > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
Dennis,
I had to repair a K3 yesterday which also was deaf. It did only receive signals > S9+40, but even for this signal the S-meter did show only S3. Following the signal of a signal Generator I found the signal to be lost at the second mixer stage. Reason was a defectice 1uF cap at the Input of the NE612 mixer U9. You can check this easily. If you look into the schematic RFboad sheet 4 of 4 right lower sector you will find U9. Measure the DC Voltages at PIN 1 and 2, it shoild be around 1,4 V. If it is zero, measure the resistance of C249, if you find it to be near or at zero, it is defective. This K3 was eorking like a champ after changing the cap. I know, there could be a lot of other reasons to find am RX deaf, but because it was not my first blown cap, i think it´s worth to be checked. 72/3 de Peter, DL2FI ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
«
Return to Elecraft
|
1 view|%1 views
| Free forum by Nabble | Edit this page |