It has a lot more L than what is used these days in many amps. In fact it is
225uH which is "coincidentally" the same as in the current Ameritrons and
copied by Alpha in their latest amps.
Carl
KM1H
----- Original Message -----
From: "Diane & Edward Swynar" <deswynar@xplornet.ca>
To: "4Z1TL" <4z1tl@iarc.org>
Cc: <amps@contesting.com>
Sent: Monday, April 25, 2011 9:20 AM
Subject: Re: [Amps] Blown anode choke TL922
> Hi Guys,
>
> I don't believe the old National R-175 / 175A had enough "L" to be
> suitable
> for 160-meters---but I could (as always) be corrected! Hi
>
> ~73~ de Eddy VE3CUI - VE3XZ
>
>
> ****************************************************************************
> *********************
>
>
> ----- Original Message -----
> From: "4Z1TL" <4z1tl@iarc.org>
> To: "Diane & Edward Swynar" <deswynar@xplornet.ca>
> Sent: Monday, April 25, 2011 3:27 AM
> Subject: Re: [Amps] Blown anode choke TL922
>
>
>> Yes - it's the TL922
>>
>> ----- Original Message -----
>> From: "Diane & Edward Swynar" <deswynar@xplornet.ca>
>> To: "Dan Hearn" <n5ardxcc@gmail.com>; "Jim W7RY" <w7ry@inbox.com>
>> Cc: <amps@contesting.com>; "4Z4TL_IARC_300" <4z4tl@iarc.org>
>> Sent: Monday, April 25, 2011 0:34
>> Subject: Re: [Amps] Blown anode choke TL922
>>
>>
>> > Hi Guys,
>> >
>> > Does that specific amplifier incorporate 160-meters...?
>> >
>> > If not, find yourself a good old National-brand R-175A plate choke (I
>> > believe that's the model/part number of it), & install it (hopefully
> it'll
>> > fit). Period.
>> >
>> > The "A" designation denotes a design change incorporated AFTER the
>> > adoption
>> > of the 15-meter band, i.e. it eliminates a resonance point found in the
>> > 21-MHz region with the original R-175 model, and so is more desirable.
>> >
>> > I have a friend who is parting-out the remains of an estate sale---and
>> > a
>> > National choke is still a part of the left-overs (not sure if it was an
>> > "A"
>> > model, or not). Sounds like a painless solution to me...!
>> >
>> > ~73~ de Eddy VE3CUI - VE3XZ
>> >
>> >
>> >
> ****************************************************************************
>> > ********************
>> >
>> > ----- Original Message -----
>> > From: "Dan Hearn" <n5ardxcc@gmail.com>
>> > To: "Jim W7RY" <w7ry@inbox.com>
>> > Cc: <amps@contesting.com>; "4Z4TL_IARC_300" <4z4tl@iarc.org>
>> > Sent: Sunday, April 24, 2011 5:21 PM
>> > Subject: Re: [Amps] Blown anode choke TL922
>> >
>> >
>> >> No one has mentioned between turn capacitance. This could be a factor
> if
>> > the
>> >> wire insulation is not the same material and thickness as the choke
>> >> you
>> > are
>> >> trying to copy.
>> >>
>> >> 73, Dan, N5AR
>> >>
>> >> On Sun, Apr 24, 2011 at 1:21 PM, Jim W7RY <w7ry@inbox.com> wrote:
>> >>
>> >> > Isaac.
>> >> > I attempted to re-wind an Ameritron choke and was not too
> successful.
>> >> > I
>> >> > did
>> >> > not have the EXACT size wire that was on the original choke. That
> makes
>> > a
>> >> > huge difference.
>> >> >
>> >> > I would attempt to re-wind your choke or just replace it with an
>> > Ameritron
>> >> > choke. I understand you're not in America but it may be worth it.
>> >> >
>> >> > Please keep us informed and good luck!
>> >> >
>> >> > Jim
>> >> >
>> >> >
>> >> > --------------------------------------------------
>> >> > From: "4Z4TL_IARC_300" <4z4tl@iarc.org>
>> >> > Sent: Sunday, April 24, 2011 12:01 AM
>> >> > To: <amps@contesting.com>
>> >> > Cc: <w7ry@inbox.com>
>> >> > Subject: Re: Blown anode choke TL922
>> >> >
>> >> > > Hi Jim
>> >> > > The choke is a home-made replica (quite close) of the original
> stock.
>> >> > > I wounded it myself, but never evaluated it with a Dip meter.
>> >> > > (I counted turns, measured spacings, wire diameter & inductance, &
>> > copied
>> >> > > it to my best ability).
>> >> > >
>> >> > > In the last 2-3 months main bands were 20,15,10 & 12, mostly in
> RTTY
>> > at
>> >> > > 400-600w out.
>> >> > >
>> >> > > The amp was on 20m when this happened, no TX. I just flipped from
> SSB
>> > to
>> >> > > CW intending to QRT.
>> >> > > Since the prolonged heating is obvious, I think this has been
>> >> > > building
>> > up
>> >> > > for the last weeks / months.
>> >> > >
>> >> > > MODS to the amp are numerous: pse see a page I prepared a year ago
>> > after
>> >> > > finishing the work :
>> >> > > http://www.iarc.org/~4z4tl/TL922/index.html
>> >> > > Tks , Isaac 4Z1TL
>> >> > >
>> >> > >> Date: Sat, 23 Apr 2011 07:50:47 -0700
>> >> > >> From: "Jim W7RY" <w7ry@inbox.com>
>> >> > >> Subject: Re: [Amps] Blown anode choke TL922
>> >> > >> To: "4Z4TL_IARC_300" <4z4tl@iarc.org>, <amps@contesting.com>
>> >> > >>
>> >> > >> What frequency have you been operating on? What other sort of
>> >> > >> mods
>> > have
>> >> > >> been
>> >> > >> to the amplifier? Is the plate choke stock or has it been
>> >> > >> rewound?
>> >> > >> 73
>> >> > >> Jim W7RY
>> >> > >
>> >> > >
>> >> > >
>> >> > >
>> >> > > -----
>> >> > > No virus found in this message.
>> >> > > Checked by AVG - www.avg.com
>> >> > > Version: 10.0.1321 / Virus Database: 1500/3593 - Release Date:
>> > 04/23/11
>> >> > >
>> >> > _______________________________________________
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>> >> >
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>> >
>>
>
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