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Re: [TenTec] TenTec Digest, Vol 63, Issue 7

To: <tentec@contesting.com>
Subject: Re: [TenTec] TenTec Digest, Vol 63, Issue 7
From: "jhreed" <jhreed@chilitech.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 5 Mar 2008 12:34:05 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
Did you mean 99.0 watts?
  ----- Original Message ----- 
  From: tentec-request@contesting.com 
  To: tentec@contesting.com 
  Sent: Wednesday, March 05, 2008 12:00
  Subject: TenTec Digest, Vol 63, Issue 7


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  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@Blomand.net>
  Subject: Re: [TenTec] Voltage drop
  To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
  Message-ID: <006601c87ece$6809bad0$c1b34ace@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@msn.com>
  To: "Discussion of Ten-Tec Equipment" <tentec@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@contesting.com
  > http://lists.contesting.com/mailman/listinfo/tentec
  > 




  ------------------------------

  Message: 2
  Date: Wed, 05 Mar 2008 10:11:25 -0500
  From: "Gary Smith" <Gary@doctorgary.net>
  Subject: Re: [TenTec] OT
  To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
  Message-ID: <47CE71CD.22694.39B48F6@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@storm.weather.net>
  Subject: Re: [TenTec] 238 Tuner Mod
  To: tentec@contesting.com
  Message-ID: <1204733253.4718.2.camel@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@yourlink.ca>
  Subject: Re: [TenTec] proper caps for Omni V?-->  Sanyo Oscon
  To: tentec@contesting.com
  Message-ID: <47CEC68C.3060608@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@storm.weather.net>
  Subject: Re: [TenTec] 238 Tuner Mod
  To: tentec@contesting.com
  Message-ID: <1204733620.4718.8.camel@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@storm.weather.net>
  Subject: Re: [TenTec] 238 Tuner Mod
  To: tentec@contesting.com
  Message-ID: <1204734118.4718.16.camel@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@mtbluesky.com>
  Subject: Re: [TenTec] proper caps for Omni V?-->  Sanyo Oscon
  To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
  Message-ID: <47CECEC1.9040207@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


  ------------------------------

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  End of TenTec Digest, Vol 63, Issue 7
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