Re: [Elecraft] How do I know if my K2 has BFOMDKT installed?
Correct Andrew. Even if it is a 10K RP you'll still want to add R19. I just got done fully upgrading a field test K2 here and had 100K stuck in my head. But it is the same whether 100K or 10K RP's. 73, Dave, W8FGU On 7/22/2022 10:52:06 AM, "Andrew Moore" wrote: Hi Dave - My s/n 892 currently has RP2 = 10k, not 100k. Does the 2.7k still need to be added across pins 7 and 8? From the PLL Ref Upgrade kit docs (E850138), it sounds like it might need to be added regardless of 10k/100k, as the first step below doesn't differentiate, while the next step does: [_] If your K2 serial number is lower than 3000, make sure you have installed the BFO modification (BFOMDKT). One of the items supplied in this kit is a 2.7-k resistor. This resistor, designated R19, must be soldered across pins 7 and 8 of resistor network WP2 (in the PLL area). [_] If you have an older K2 (early revision A for Field Test), you may have a 100k resistor network installed at RP2, which is in the VCO area. If so, you'll need to solder two 10k to 12k resistors across RP2, which can be difficult... Thanks, -Andrew NV1B .. On Fri, Jul 22, 2022 at 9:30 AM Dave Van Wallaghen wrote: Hi Andrew, Yes, place that 2.7KΩ resistor across RP2 pins 7 & 8. This resistor is on the output of U6A to drive the varactor diodes in the PLL Osciillator circuit. It was changed to 2.7K in Rev B. In Rev A it was 100K and part of RP2, so you are just placing a 2.7k resistor in parallel with the 100K on RP2 P& and P8. I believe the change was to help add stability to the PLL Oscillator circuit. 73, Dave, W8FGU On 7/21/2022 11:04:58 PM, "Andrew Moore" wrote: >I just installed the temperature compensated PLL reference upgrade kit on >my K2 #892. > >From everything I can see, this rig (which I bought used) has been brought >up to date in almost every way. > >One step in the assembly instructions says that for S/N < 3000, make sure >I've installed the BFOMDKT upgrade, and that the kit includes a 2.7k >resistor R19 that's soldered across pins 7 and 8 of RP2 (according to >document "Upgrading the Elecraft K2 to Revision B"). > >My RP2 (10K) has no resistor across any pins. However, I do have L33 >upgraded to the prewound 41 uH inductor, which I think was part of the >BFOMDKT. > >Should I be adding 2.7k across pins 7 and 8? Is there any reason this would >not have been done as part of the BFOMDKIT upgrade? > >Thanks, >-Andrew NV1B >.. >__ >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 >Message delivered to d...@w8fgu.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] How do I know if my K2 has BFOMDKT installed?
Hi Dave - My s/n 892 currently has RP2 = 10k, not 100k. Does the 2.7k still need to be added across pins 7 and 8? From the PLL Ref Upgrade kit docs (E850138), it sounds like it might need to be added regardless of 10k/100k, as the first step below doesn't differentiate, while the next step does: [_] If your K2 serial number is lower than 3000, make sure you have installed the BFO modification (BFOMDKT). One of the items supplied in this kit is a 2.7-k resistor. This resistor, designated R19, must be soldered across pins 7 and 8 of resistor network WP2 (in the PLL area). [_] If you have an older K2 (early revision A for Field Test), you may have a 100k resistor network installed at RP2, which is in the VCO area. If so, you'll need to solder two 10k to 12k resistors across RP2, which can be difficult... Thanks, -Andrew NV1B .. On Fri, Jul 22, 2022 at 9:30 AM Dave Van Wallaghen wrote: > Hi Andrew, > > Yes, place that 2.7KΩ resistor across RP2 pins 7 & 8. This resistor is > on the output of U6A to drive the varactor diodes in the PLL Osciillator > circuit. It was changed to 2.7K in Rev B. In Rev A it was 100K and part > of RP2, so you are just placing a 2.7k resistor in parallel with the > 100K on RP2 P& and P8. I believe the change was to help add stability to > the PLL Oscillator circuit. > > 73, > Dave, W8FGU > > > On 7/21/2022 11:04:58 PM, "Andrew Moore" wrote: > > >I just installed the temperature compensated PLL reference upgrade kit on > >my K2 #892. > > > >From everything I can see, this rig (which I bought used) has been brought > >up to date in almost every way. > > > >One step in the assembly instructions says that for S/N < 3000, make sure > >I've installed the BFOMDKT upgrade, and that the kit includes a 2.7k > >resistor R19 that's soldered across pins 7 and 8 of RP2 (according to > >document "Upgrading the Elecraft K2 to Revision B"). > > > >My RP2 (10K) has no resistor across any pins. However, I do have L33 > >upgraded to the prewound 41 uH inductor, which I think was part of the > >BFOMDKT. > > > >Should I be adding 2.7k across pins 7 and 8? Is there any reason this > would > >not have been done as part of the BFOMDKIT upgrade? > > > >Thanks, > >-Andrew NV1B > >.. > >__ > >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 > >Message delivered to d...@w8fgu.com > > __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] How do I know if my K2 has BFOMDKT installed?
Hi Andrew, Yes, place that 2.7KΩ resistor across RP2 pins 7 & 8. This resistor is on the output of U6A to drive the varactor diodes in the PLL Osciillator circuit. It was changed to 2.7K in Rev B. In Rev A it was 100K and part of RP2, so you are just placing a 2.7k resistor in parallel with the 100K on RP2 P& and P8. I believe the change was to help add stability to the PLL Oscillator circuit. 73, Dave, W8FGU On 7/21/2022 11:04:58 PM, "Andrew Moore" wrote: I just installed the temperature compensated PLL reference upgrade kit on my K2 #892. From everything I can see, this rig (which I bought used) has been brought up to date in almost every way. One step in the assembly instructions says that for S/N < 3000, make sure I've installed the BFOMDKT upgrade, and that the kit includes a 2.7k resistor R19 that's soldered across pins 7 and 8 of RP2 (according to document "Upgrading the Elecraft K2 to Revision B"). My RP2 (10K) has no resistor across any pins. However, I do have L33 upgraded to the prewound 41 uH inductor, which I think was part of the BFOMDKT. Should I be adding 2.7k across pins 7 and 8? Is there any reason this would not have been done as part of the BFOMDKIT upgrade? Thanks, -Andrew NV1B .. __ 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 Message delivered to d...@w8fgu.com __ 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 Message delivered to arch...@mail-archive.com
