The Isotemp 134-10 *may* have a screw in the side of the case that gives access to a trimmer for the frequency. You can set your Fury to an EFC output of 2.5V and try adjusting the trimmer for 10MHz or as close as you can get it. This will optimize your control range from the Fury, with the proviso that the Isotemp's control slope is not linear. My OFC version does not have the access port, but it it a much earlier model than the Isotemp 134. The Isotemp has a positive control slope -- increasing EFC increases frequency. Mine has an EFC sensitivity of about 2E-7 per Volt. Dick Moore > From: Matt Osborn <_kc0ukk@msosborn.com_ > (mailto:kc0ukk@msosborn.com) > > Date: November 1, 2008 23:28:34 PDT > To: time-nuts <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > > Subject: [time-nuts] Jackson Labs Fury & Isotemp OCXO134-10 > Reply-To: Discussion of precise time and frequency measurement > <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > > > I think that I've managed to keep a low profile here, trusting that I > would learn more if I refrained from random interjections of > ill-informed thoughts. However, there comes a point in every man's > life... > > A year or two ago, I took advantage of Said's offer and purchased one > of the Jackson Labs OEM external OCXO Fury units and am > attempting to > put it to work. I've decided to use an Isotemp OCXO134-10 oscillator > and have several decisions which I would like to vet with those of > you > that have been down this road before. > > The Isotemp unit has an EFC range of 0 to 8 Volts; the Fury has an > EFC > range of 0 to 5 volts. Using my HP 53131A, I'm able to adjust the > Isotemp to 10 MHz +- 5 mHz with an EFC voltage of 4.64 volts. > That is > within the adjustment range of the Fury, but I'm not sure of the > accuracy of the HP53131A. Should I construct a resistive network ala > Brooks Shera to 'boost' the EFC range just in case or would I be > better off just using the Fury 'as is'? > > Secondly, the Jackson Labs advises that since the Fury uses the > external oscillator as its clock, that the oscillator should be > powered up before the Fury itself. I was hoping that I would be able > to use a single power switch to power both the oscillator and the > Fury > simultaneously, but now I'm not so sure. > > Finally, are there any of you that have used the Isotemp OXCO134-10 > with the Fury? Have any of you worked out the various SERVO settings > that the Fury makes available? I'm interested in the DAC gain, EFC > scale, EFC dampening and Phase compensation. > > Any and all advice will be gratefully accepted. > > -- kc0ukk at msosborn dot com >