[time-nuts] Minicircuits specs

Gerhard Hoffmann dk4xp at arcor.de
Mon Dec 8 01:14:50 EST 2014

Am 29.11.2014 um 20:01 schrieb Gerhard Hoffmann:
> Am 29.11.2014 um 19:08 schrieb Thomas S. Knutsen:
>> 2014-11-29 16:24 GMT+01:00 Dave M <dgminala at mediacombb.net>:
>> Yeah, that's a good way to completely avoid the issue.  Since I'm the 
>> only
>> target audience for my efforts, then I don't mind the extra components.
>> I'm beginning to realize, as I get deeper into building my own stuff, 
>> that
>> a VNA is quite a desireable piece of equipment.  Unfortunately, I'll 
>> have
>> to make use of my spectrum analyzer and RLC meters instead.
> Ok, I volunteer to measure the S21 of a dc-force-fed T1-1 or T4-1 next 
> weekend, when
> I'm back home.  (DG8SAQ VNWA and / or W&G TSA-2)
> Really, on osc, a voltmeter and a DC source are enough.

Here it is:   Mini circuits T1-1T, new very old stock, still in black 
case, not
one of the new whitish ones that turn brown in the week after soldering.

0 / 25 / 50 / 100 mA on the secondary side from Agilent 6633B dc supply.
It is nice that you can directly type in the voltages or currents.
But you better do not take this thing for anything that is sensitive to 

DG8SAQ VNWA, my best DC block from PSPL because it also has the
lowest lower corner. It took some experimenting to find a choke that
would not modify S21 and carry the current. Finally: a medium size
red Amidon core & two 220uH Siemens chokes with a looong air gap.


The low frequency corner suffers already at 25 mA. The high frequency side
is unimpressed by the current. Just what one expects from a transmission 
transformer that gets ferrite as an anabolicum for the low frequencies.

The transformer survived 1A for a short time and did not seem to suffer
from that abuse s-parameter-wise.

regards, Gerhard

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