[Drake] Drake 2B s meter

[Heinz Breuer]

Well it depends. My HP410B VTVM has an input impedance of 122 Megaohm in all DC ranges. My handheld Fluke 77 DVM has only 10 Megaohm which will certainly load down the AGC line.
My old HP3455A desktop DVM has an input impedance >10^10 Ohms in DC ranges 0.1 V to 10 V and 10 Megaohm in ranges 100 V and 1000 V.
Always check the manual.

vy 73 Heinz DH2FA, KM5VT
Von meinem iPhone gesendet

> Am 19.12.2014 um 01:54 schrieb Stephanie WX3K <wx3k at ptd.net>:
> 
> I disagree. DVMs have a high input impedance and therefore can be used 
> 
> Stephanie WX3K
> 
>> On Dec 15, 2014, at 6:54 PM, Tony Sokol <tonysokol at sbcglobal.net> wrote:
>> 
>> Hi Dave,
>> 
>> In my notes I read an addendum that suggested 1.35 V instead of 1.5 V for the AVC. Also don't forget that you MUST use a VTVM instead of a standard DVM. You are measuring a very high impedance circuit and anything other than a VTVM will load the circuit down.  
>> I am sure you are setting the S meter pot  20DB over S9 on the calibrate signal with the pot that is located through the hole on the lower left corner of the front panel...right?  The one on the rear panel is to set the 1.35 V level measured the AVC terminal on the back.  
>> 
>> 73
>> Tony - W9JXN
>> 
>> 
>> 
>> Sent from my iPhone
>> 
>>> On Dec 15, 2014, at 5:32 PM, <dave.varner at charter.net> <dave.varner at charter.net> wrote:
>>> 
>>> I was getting bored with my high tech ham radio and decided to put together a vintage station. I bought a nice Ranger a few months ago and plan to use it with a Drake 2B that was given to me several years ago. It was very clean inside and out. I replaced the recommended caps which got rid of the awful hum. I replaced several tubes which got the AVC voltage to the correct value (-1.5v) and got the standby function working. It has plenty of gain. I can hear everything that my Icom hears but not with the same selectivity, of course. However, the s meter hardly registers except with very strong signals. The one problem I have identified is that the voltage on pin 1 of V3 is supposed to be –0.5v and mine is around 2.7v (it is not a constant value and sometimes goes up to 3v). The voltages on the other pins of V3 are OK.  I do not have the correct meter to measure leaky caps. I have seen others suggest swapping the 6U8 (I sm using 6U8A) with a 6EA8 . I plan on doing that. I have also not replaced the 6BZ6 rf amp tube. Also, the s meter cal switch on the back has no effect on the s meter. I have done what the manual says (on 80m with no ant. adjust the pot to 20db over s 9) and still no improvement. I have looked pretty hard for other hams comments and nothing other than a leaky cap seeems to be a solution now (unless the two tubes I mentioned help). If anyone has had the same issue, I sure would appreciate some advice
>>> On another topic, I wonder what kind of T/R arrangement others are using. I have seen an rf T/R switch from MFJ mod. 1708. It has been several decades since I
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