Gerhard Hoffmann wrote:

Thanks Gerhard, but I can't get that link to work.  It sends me to Google,
which tells me that I need to enable Javascript.  Javascript has been turned
on and running on my system for years, but apparently, that link doesn't see
it.

Dave M

Hi

The link animates a Google search for the part number. The first thing that comes up here is the standard Mini-Circuits spec sheet for the part. It’s got the usual S parameter data, but nothing on DC current.

Bob

Bob Camp wrote:

Thanks for clearing that up, Bob.  I have had the spec sheet for quite a
while, but its only mention of DC current is the Max DC spec of 30ma, but no
data describing the effects of it on the device's performance.

Dave M

Hi

My past experience with Minicircuits is that they will not give you any data the “extends” the spec on a part. Simply put - if you are after 1 MHz data on a part that stops at 10, they are not likely to supply it. I guess the policy is in place so they don’t wind up with parts spec’d outside their normal range.

I’d still give them a call, the policy may have changed, or it may not apply to current …

Bob

Bob wrote:

I've had better luck getting data from them that is just not stated
(as opposed to being outside a stated spec) -- for example, the
nominal inductance of windings.  I suspect the same might be true if
someone asked, "What exactly do you mean by 'DC: 30mA?' "  You
probably wouldn't get hard data or graphs, but they might give you an
idea of how they arrived at that spec.

In the end, though, the only way to be sure a certain part will work
in any particular circuit is to build and test it.

Don't forget, you can generally keep DC out of transformer windings
with shunt coupling (use an RF choke for the DC path, and capacitor
couple into the transformer winding).  It's an unwanted complexity,
but some builders may prefer it to winding their own transformers.

Best regards,

Charles

Charles Steinmetz wrote:

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.

Thanks for the responses.
Dave M

2014-11-29 16:24 GMT+01:00 Dave M dgminala@mediacombb.net:

Going a bit off topic, but there are decent VNA's avaible for an fair
price. There is the N2PK VNA thats avaible as an board + digikey partlist
and gives a 120dB dynamic range VNA from 10KHz to 50MHz, or there are the
VNWA avaible ready buildt from the UK with 70-80dB dynamic range to 1.3GHz.
Those are the ones I know that have true phase reading and can solve for
the sign of the phase.

Of course there are older HP or R&S boxes, and probably others as well, and
by shopping around one can get decent gear at a fair price, but with some
added complexity of doing the measurments.
Having an VNA helps doing measurments, but a lot of cool things can be done
with a spectrum analyzer, adding a simple return loss bridge makes that
into an quite decent scalar VNA.

Brr. (its probably cold up here in the north :)
Thomas LA3PNA.

--

Please  avoid sending  me  Word  or  PowerPoint  attachments.
See  http://www.gnu.org/philosophy/no-word-attachments.html
PDF is an better alternative and there are always LaTeX!

On 11/29/2014 12:08 PM, Thomas S. Knutsen wrote:

Or the DG8SAQ 1.3 GHz VNA for about £350 GBP or ~$550 I suspect this is
what you are calling the "VNWA available ready built from the UK with
70-80dB dynamic range to 1.3GHz."

http://sdr-kits.net/VNWA3_Description.html

--
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Oz
POB 93167
Southlake, TX 76092 (Near DFW Airport)

Am 29.11.2014 um 19:08 schrieb Thomas S. Knutsen:

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.

Not only there. I was this afternoon for 3 hours with a motor bike on the
Suebian Alp in southern Germany, just 3°C above the freezing point.
The last half hour was not so pleasant.

regards, Gerhard, dk4xp

On 27 Nov 2014 13:56, "Jim Lux" jimlux@earthlink.net wrote:

any Mini-Circuits catalog model from our web store on minicircuits.com will
receive a 10% *discount!

I thought I would place my order online to get the discount,  whereas I
normally do by phone.

I decided to order from the USA rather than the UK. MiniCircuits charged me
$102 to ship twelve SMA terminations and ten N terminations by UPS. That is
their "shipping & handling change".

I could send the same bits from the UK to the USA for less than 50% of that
and I don't have a UPS account.  A UPS account holder would get a better
rate.

I can get free shipping in the UK if I spend more than some relatively
small amount,  but I pay a lot more for the parts. Minicircuits use an
exchange rate of close to 1 USD = 1 GBP.

I seem to be between a rock and a hard place - either pay a ridiculous
exchange rate,  or pay a ridiculous shipping & handling cost.

Dave, G8WRB.