[Johnson] Attenuator, connectors for Thunderbolt

[Mahlon Haunschild]

Steve,

Insofar as the (unobtainable) attenuator is concerned, you're probably
better off making your own from the schematic in the manual.  Use
Panasonic metal-oxide-film or Sprague OY-series resistors, either type
should be sufficiently non-inductive for this purpose.  Both available
from Digi-Key.

For the bias connector, you can use the four-pin insert from the
Amphenol microphone plug used on gazillions of Motorola 2-way (Motrac,
et al) microphones.  The "proper" connector uses this exact same insert,
but with a small backshell.

Do you have an early (oil HV capacitor) or late (electrolytic HV
capacitors) Thunderbolt?  If early, there are one or two changes you
should make to update it to the later design to keep you screen & bias
supplies happy.  Check the list archives for details.

regards,

Mahlon - K4OQ

> --__--__--
> 
> Message: 1
> Date: Mon, 26 May 2003 09:39:43 -0700 (PDT)
> From: Stephen Victor <victorsj@yahoo.com>
> To: johnson@mailman.qth.net
> Subject: [Johnson] Attenuator, connectors for Thunderbolt
> 
> Hi
> Does anyone know where I can obtain the T-pad
> attenuator for interfacing the Ranger with the
> Thunderbolt (Johnson cat. no. 250-42-1)?
> Also, the octal plugs for the bias cable connections?
> Thanks and 73
> Steve
> WA2DTW