[Elecraft] K3 Buffer Mod

[Don Wilhelm]

Jerry,

I do agree with you.  There is a requirement for an isolation amplifier 
anyhow, so I do not understand why the -17.7 dB cannot be made up in the 
isolation amplifier if the device to be driven needs  input at the same 
level as the antenna signal.

Should Elecraft ever come out with a device (Panadapter?) that is 
designed to connect to the IF out at the level it currently is designed 
for, any K3 that has been modified will require that the modification be 
  removed.

73,
Don W3FPR

Jerry Flanders wrote:
> 
>>
>> Don Rasmussen wrote:
>> >
>> >
>> > I have the LP-Pan with recommended Creative Labs E-MU
>> > 0202 and find this to be optimal, I mean no reason to
>> > make a mod of any type to K3. If someone told you that
>> > this must be done, I'd want to see why with my own
>> > eyes before doing this job.
>> >
> 
> 
>> At 08:16 AM 8/22/2008, Bill W4ZV wrote:
>> 17.7 dB transfer loss from RF IN to IF OUT is why...
> 
> But isn't that just an engineering design decision made by the Elecraft 
> team? Since that decision was (hopefully) made with regard to the entire 
> radio system, isn't that decision likely to be a good one?
> 
> As one data point, my K3 is not modified, yet the IF panadaptor works 
> extremely well, and PowerSDR gives peak heights approximating the true 
> signal strengths seen at the input of the K3. When I feed in a 1 uV 
> signal from my KG-2 signal generator, I see a definite distinct peak on 
> the panadaptor, and when I feed in a 50 uV (S9) signal, I see a large S9 
> signal on the panadaptor.
> 
> I am a loss to understand why you guys are quarreling with the Elecraft 
> design in this instance. I am beginning to suspect that it is simply 
> because it does not agree with the usual designs provided by some 
> military contractors who are probably using an _arbitrary_ "standard" 
> anyway.
> 
> I would think twice before possibly damaging my radio or lowering its 
> resale value with non-factory authorized modifications.
> 
> YMMV.
> 
> Jerry W4UK