[TenTec] TenTec Digest, Vol 63, Issue 7
jhreed
jhreed at chilitech.net
Wed Mar 5 12:34:05 EST 2008
Did you mean 99.0 watts?
----- Original Message -----
From: tentec-request at contesting.com
To: tentec at contesting.com
Sent: Wednesday, March 05, 2008 12:00
Subject: TenTec Digest, Vol 63, Issue 7
Send TenTec mailing list submissions to
tentec at contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/tentec
or, via email, send a message with subject or body 'help' to
tentec-request at contesting.com
You can reach the person managing the list at
tentec-owner at contesting.com
When replying, please edit your Subject line so it is more specific
than "Re: Contents of TenTec digest..."
Today's Topics:
1. Re: Voltage drop (Bob McGraw - K4TAX)
2. Re: OT (Gary Smith)
3. Re: 238 Tuner Mod (Dr. Gerald N. Johnson)
4. Re: proper caps for Omni V?--> Sanyo Oscon (Hutchinson)
5. Re: 238 Tuner Mod (Dr. Gerald N. Johnson)
6. Re: 238 Tuner Mod (Dr. Gerald N. Johnson)
7. Re: proper caps for Omni V?--> Sanyo Oscon (Doug Smith)
----------------------------------------------------------------------
Message: 1
Date: Wed, 5 Mar 2008 08:37:14 -0600
From: "Bob McGraw - K4TAX" <RMcGraw at Blomand.net>
Subject: Re: [TenTec] Voltage drop
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Message-ID: <006601c87ece$6809bad0$c1b34ace at FAMILY>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Ideally there should be none.
However, in practice, and we'll presume you are referencing the voltage
required to operate a 12 volt DC 100 watt transceiver, then 0.1 to 0.2 volts
would normally be acceptable. This is about 1% {13.8 * 1% = 0.138} If
every thing operates in a straight line fashion, then the output of the
radio would not be 100 watts but less 10% or 90 watts. Then we get into the
dynamic regulation caused by the changing load due to CW or voice peaks.
Short power leads, good power supply regulation and #12 wire for runs of 6
ft or less work quite well. Be sure all terminals are soldered and not just
crimped. Makes for lower IR loss.
73
Bob, K4TAX
----- Original Message -----
From: "Bill Harris" <w7kxb at msn.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Wednesday, March 05, 2008 1:58 AM
Subject: [TenTec] Voltage drop
>
> Is there a rule of thumb for maximum voltage drop through the primary DC
> power lead.
>
> 73
> BillHarris w7kxb
>
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
------------------------------
Message: 2
Date: Wed, 05 Mar 2008 10:11:25 -0500
From: "Gary Smith" <Gary at doctorgary.net>
Subject: Re: [TenTec] OT
To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
Message-ID: <47CE71CD.22694.39B48F6 at Gary.doctorgary.net>
Content-Type: text/plain; charset=US-ASCII
Ionizers send out ions which are charged particles. They are
attracted to tiny particles floating in the air be it dust, mite
dander, whatever. This particle is now larger and has more weight.
More ions are attracted and cling to this larger particle and the
particle is inclined to fall to ground thanks to gravity or attach
itself to a solid object.
Inhalation of such charged particles causes them to attach to lung
tissue with some micro trauma and cellular changes. Not good. The
same for the attachment to the skin; many of the same issues related
to smoking. You'll see walls and objects near to the ionizer become
darker and this is from the attachment the charged particles to the
wall.
Do a google search for "Free Radicals" and the information should be
of interest. A brief answer is
here:http://www.healthchecksystems.com/antioxid.htm
If you look at the newer Ionizers sold by Sharper Image you'll see an
attachment the older ones did not have and this I believe is supposed
to deal with the release of charged particles.
Be aware you can't avoid these ionized particles and they are 9or
were) commonly used by larger stores to process their air and give an
fresh & invigorating feel the customer perceives when walking into
the store. Electrostatic air filters create these particles.
Ozone production is greatly affected by the voltage oxygen encounters
and I do not recall the specifics but ionizers of the sort allowed
for sale be it from the Sharper Image or from your electrostatic air
filter; are maxed at something around 5KV and much more than this
rips the Oxygen molecule apart and creates the abundant Ozone that is
harmful.
There is a difference between a charged particle and Ozone. It's that
old drill; All charged particles are not Ozone but all Ozone are
charged particles.
Gary
Who was a lucky one to work VP6DX on 160, barefoot from CT with his
Omni V
> Ok I admit it I am a knuckle dragger ... Is that how Ionizers made to
> clean air work by creating Ozone ?
------------------------------
Message: 3
Date: Wed, 05 Mar 2008 10:07:33 -0600
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
Subject: Re: [TenTec] 238 Tuner Mod
To: tentec at contesting.com
Message-ID: <1204733253.4718.2.camel at host.domain.com>
Content-Type: text/plain
On Tue, 2008-03-04 at 19:28 -0800, Ron Castro wrote:
> I think the cost calculation was the bigger driving force in that decision!
>
> Ron N6IE
> www.N6IE.com
>
I've heard many an engineer's tale where a quality capacitor was
specified and necessary and purchasing bought something a great deal
cheaper. Sometimes wasting months of engineering time waiting for the
quality capacitor to be made, once management convinced purchasing that
the expensive capacitor couldn't be replaced by a 29 cent part.
73, Jerry, K0CQ
------------------------------
Message: 4
Date: Wed, 05 Mar 2008 10:13:00 -0600
From: Hutchinson <Hutchinson at yourlink.ca>
Subject: Re: [TenTec] proper caps for Omni V?--> Sanyo Oscon
To: tentec at contesting.com
Message-ID: <47CEC68C.3060608 at yourlink.ca>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Joe,
Thanks for that information.on Sanyo Oscons I did a Google search for
them and came up with some interesting reading.
http://us.sanyo.com/industrial/electronic_components/capacitors/os_con/overview.cfm
Lots of good stuff (in PDF format) to look at and read.
A question was asked regarding where they (not necessarily the Sanyo
caps but low ESR caps in general)
may NOT be the best choice, and thats covered on the Sanyo site too, so
you may want to read the "precautions"
PDF. Basically it says due to low ESR, consideration must be given to
circuits that are sensitive to inrush current.
In those circuits, you just have to design things a with a bit of
forethought, keeping inrush current in mind.
http://us.sanyo.com/industrial/electronic_components/capacitors/os_con/downloads/oscon_precautions.pdf
Since I'm on daily digest mode, if this has been answered already,
please forgive the repeat. Great subject. I'm
certainly enjoying a good discussion, and its got me considering
recapping my Corsair II.
73 Dave
VE5AEA
------------------------------
Message: 5
Date: Wed, 05 Mar 2008 10:13:40 -0600
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
Subject: Re: [TenTec] 238 Tuner Mod
To: tentec at contesting.com
Message-ID: <1204733620.4718.8.camel at host.domain.com>
Content-Type: text/plain
On Tue, 2008-03-04 at 07:45 -0800, Jim Brown K9YC wrote:
> On Tue, 4 Mar 2008 09:55:27 -0500, Jack Mandelman wrote:
>
> >However, instead of using
> >doorknob caps I replaced the originals with 6KV 470pF Y5P ceramics.
>
> It's no surprise that the original caps, which have a fairly high
> negative temperature characteristic, change value as they warm up --
> they are SPECIFIED to do that. :) I'm wondering if it was a pricing
> decision by Ten Tec to use them, or if the designer was attempting
> to compensate for heat-related drift in the other direction by the
> inductor?
>
> 73,
>
> Jim K9YC
>
>
No coil is that temperature sensitive. The change in capacitance by
ordinary (bypass and coupling grade) ceramic capacitors is dramatic, and
much as an 80% loss of C going from room temp to 85 C. I learned about
that long ago, tucking a little GP dog bone against an IF tube socket.
Then I took it out and put it on a bridge and applied heat. I learned
that the compact capacitor tended to have a very high temperature
coefficient, a characteristic of the high dielectric constant ceramic
used to make it small, and also was piezo electric.
73, Jerry, K0CQ
------------------------------
Message: 6
Date: Wed, 05 Mar 2008 10:21:58 -0600
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
Subject: Re: [TenTec] 238 Tuner Mod
To: tentec at contesting.com
Message-ID: <1204734118.4718.16.camel at host.domain.com>
Content-Type: text/plain
On Tue, 2008-03-04 at 14:37 -0700, pfizenmayer wrote:
> Guess there must be 238's, 238A's and 238B's - I have one I bought new
> circa Feb 2005 called 238B SN 09C10104 where the padders on the Schematic
> are shown as 2 each 220 pfd in parallel in each location.
>
> The parts list says they are 180 pfd and my unit has 150 pfd. The variable
> cap is shown as 40 - 500 pfd. I suspect the reason they kept sneaking the
> value of the paralleled caps lower and lower is that the stray inductance
> and the little network inserted to tune out the residual SWR makes the
> paralleled values look larger than the actual capacitance.
I don't think so. Its probably that the variable capacitor didn't have
the delta range planned for as its supplier changed and its plate
spacing was increased to handle the voltage better. And you don't want
the switched capacitors to have a bigger jump than the delta range of
the variable.
> And even at 150
> pfd paralleled in each section I have many cases where for instance LOZ-1
> will not quite match at max variable capacitance even on 80 meters and LOZ-2
> is too much capacitance.(var cap at minimum is too much ) No huge deal as
> the final SWR is less than 1.3 :1 but often thats as close as you can get.
>
> Anyhow - I also suspect the paralleled caps instead of single caps helps the
> "drift" substantially.
For sure the paralleled capacitors divides the current between them and
so the heating. And NPO capacitors are easier to find in the smaller
values.
> I have never noticed any drift with the settings I
> have to use with my dipoles at a kw. Usually in LOZ1 or 2. On 160 the
> configuration I have makes me have to add another CM45 2000 pfd externally
> and using that I still notice no drift at a kw.
But the CM45 is mica, a whole lot more stable than the general purpose
ceramic dielectric.
>
> 73 de Hank K7HP
>
73, Jerry, K0CQ
------------------------------
Message: 7
Date: Wed, 05 Mar 2008 09:48:01 -0700
From: Doug Smith <doug at mtbluesky.com>
Subject: Re: [TenTec] proper caps for Omni V?--> Sanyo Oscon
To: Discussion of Ten-Tec Equipment <tentec at contesting.com>
Message-ID: <47CECEC1.9040207 at MTBlueSky.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Dave wrote:
>
> I'm certainly enjoying a good discussion, and its got me considering
> recapping my Corsair II.
This *is* a good discussion and I'm also enjoying it. Thank you for
posting the Sanyo links.
For anyone who carries through with a re-capping project it would be great
to post their parts list and parts source info. That info would be a big
help to anyone who later contemplates doing the same thing.
Thanks to everyone for their contribution to this discussion.
73,
-Doug, W7KF
------------------------------
_______________________________________________
TenTec mailing list
TenTec at contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
End of TenTec Digest, Vol 63, Issue 7
*************************************
_______________________________________
No viruses found in this incoming message
Scanned by iolo AntiVirus 1.5.2.4
http://www.iolo.com
More information about the TenTec
mailing list