[Heathkit] Re-Try DX-60 Plate Resting Current with VFO

[Bwana Bob]

Ken:

I'll check my DX-60A and HG-10.  My HG-10 had a drift and chirp problem 
on 15m many years ago. I found that the fault was the 6CH8 tube. 
Replacing the tube solved the drift and chirp problem.  My guess is that 
particular tube must have had an element that expanded when keyed and 
caused a shift in capacitance.

                 73,

                 Bob WB2VUF

On 4/10/2012 11:51 PM, Ken Miller K6CTW wrote:
> All:
>
> OK, let's try that again, but this time with plain text formatting.
>
> I have been working with two VFOs on my DX-60. The DX-60 is an original 1961 variant, not the later A or B models.  I have fully restored the unit and it has been working very nicely with both crystals and an HG-10B that I have also restored.  Unfortunately the HG-10B still has an unacceptable level of drift when operating on 20 and 15 meters, hence when offered a DDS VFO I built it up, added the necessary support circuitry (power and switching, keying) and have put it on-line.  I have had an interesting experiment with the DDS VFO to try to come up with an output impedance that is the equivalent to that of the cathode follower output of the HG-10B.
>
> When I run the DX-60 in CW mode, and with the key up, and the HG-10B providing frequency control, the plate meter shows a resting plate current of about 5-7 ma when loaded to 120 ma on 40 and 20 meters. When switched to the DDS VFO, the plate current is 12-15 ma.
>
> According to the manual (page 37, step 20) it says that the final plate current will be approximately 20 ma.
>
> What are you all seeing when you have your rig on?
>
> Please let me know the VFO type/model.
>
> All information appreciated. Thanks in advance.
>
> 73 - Ken Miller, K6CTW
> ______________________________________________________________
> Heathkit mailing list
> Home: http://mailman.qth.net/mailman/listinfo/heathkit
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Heathkit at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.1913 / Virus Database: 2411/4933 - Release Date: 04/12/12
>
>