[Boatanchors] Drake cable question (measured)
Ron Bussiere via Boatanchors
boatanchors at mailman.qth.net
Wed Jun 11 11:26:17 EDT 2014
Richard, thank you for the tip about the periods. I knew there had to be a way...
One last thing on the cable, since this poor equine has been flogged enough.
I do have 2 Q Meters. A nice GR and a Heathkit. I didn't even think to measure the Q of the cable.....
Lastly, what is strange about the RG-6 cable, is this stuff is supposed to be good to 2200 MHz, so it can't be too lossy... ha ha
ron
N4UE
-----Original Message-----
From: Richard Knoppow <1oldlens1 at ix.netcom.com>
To: bonddaleena <bonddaleena at aol.com>
Sent: Wed, Jun 11, 2014 12:42 am
Subject: Re: [Boatanchors] Drake cable question (measured)
----- Original Message -----
From: <bonddaleena at aol.com>
To: <1oldlens1 at ix.netcom.com>; <boatanchors at mailman.qth.net>
Sent: Tuesday, June 10, 2014 2:26 PM
Subject: Re: [Boatanchors] Drake cable question (measured)
Hi Richard, no,it doesn't measure df. I used extreme care
dressing the VERY short leads from the Leader to the cable
under test. I repeated the tests multiple times. I use this
bridge to measure ePay, er, eBay variable caps for the new
VHF linears I am building (someday) ha ha
I have used this bridge hundreds of times and measuring the
RG-6 was the only time I have ever seen this broad null. The
'tuning knob' is a 10 turn pot and it's easy to find a
normal cap's value.Normally, the 'dip' is extremely
sharp.......It went back to Leader a couple of years ago due
to trying to measure the value of an 'orange drop'... Long
story, but funny and expensive!!!
I don't know what to say... I'm sorry about the results. I
should have used a different format. What I typed in is NOT
what came out!
It's worth everything you'all paid for it.... ha ha
ron
N4UE
I didn't mean to sound critical, I was only trying to
figure out what happened. It would be interesting to
measure this cable on a regular impedance bridge like the GR
bridge or even on a General Radio XY bridge. The latter is a
PITA to use but will balance on anything including negative
values. I suspect the cable may have some sort of loss that
is keeping it from balancing on the capacitance meter.
Since you are measuring open circuit this may be loss in the
dielectric (would have to be large). Very odd. Anyway, I
don't think I would use this cable for anything.
I found for sending tables in text its sometimes helpful
to use rows of dots. I discovered this when posting
photographic developer formulas. A sample
Kodak D-76
Water (at about 125F or 52C)................750.0 ml
Metol.........................................2.0 grams
Sodium sulfite, desiccated..................100.0 grams
Hydroquinone..................................5.0 grams
Borax (granular)..............................2.0 grams
Water to make.................................1.0 liter
Use full strength of diluted 1 part stock to 1 part water.
Usually this arrangement will hold together even when
the format is changed. Let me know how it comes through.
--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com
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