TL-922 Diode replacement
Had the same problem with my TL-922A
There is a 50 amp zener diode available from Mouser that should work, have
to do
a bracket of some sort. Or you could wire a number of silicon diodes in
series to replicate the zener voltage (drop across diode) I believe I used
about
10 of the 3 amp diodes to make it work. Remember it passes same current as
the plate and rid of the 3-500Z or over an amp on some peaks.
That high current probably is what smoked the original.
Nice amp, though I sold mine when I got the AMP Supply LK-500s
Good luck!
ed K0KL
----- Original Message -----
From: <amps-request@contesting.com>
To: <amps@contesting.com>
Sent: Friday, September 07, 2007 9:13 AM
Subject: Amps Digest, Vol 57, Issue 12
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> Today's Topics:
>
> 1. Re: Zener diode for TL922 (Peter Chadwick)
> 2. Re: crossmodulation in PA (Peter Chadwick)
> 3. Re: crossmodulation in PA (Johan)
> 4. Re: 7.5V Zener 10W for TL922 (Nils Petter Pedersen)
> 5. Re: QRO or Commander (w6duv)
> 6. Re: crossmodulation in PA ? Thanks for all good ??advice
> (Tom Rauch)
> 7. Re: crossmodulation in PA (Bill Fuqua)
> 8. Re: crossmodulation in PA ? Thanks for all good ??advice (k7fm)
> 9. Re: crossmodulation in PA (jeremy-ca)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 7 Sep 2007 10:38:18 +0200 (CEST)
> From: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
> Subject: Re: [Amps] Zener diode for TL922
> To: slonim aron <as1935@012.net.il>, amps@contesting.com
> Message-ID:
> <6768214.742981189154298233.JavaMail.www@wwinf3204.me-wanadoo.net>
> Content-Type: text/plain; charset=UTF-8
>
> Aron asked:
> >Looking for 7,5 v zener 10w diode for TL922.
> wonder where i can buy them.<
> Farnell Electronics in the UK do a BZY93C7.5 10 watt stud mounted diode.
About $16.
> 73
> Peter G3RZP
>
> ------------------------------
>
> Message: 2
> Date: Fri, 7 Sep 2007 10:46:03 +0200 (CEST)
> From: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
> Subject: Re: [Amps] crossmodulation in PA
> To: amps@contesting.com
> Message-ID:
> <20434933.743561189154763146.JavaMail.www@wwinf3204.me-wanadoo.net>
> Content-Type: text/plain; charset=UTF-8
>
> Over the years, this has been a well known problem on ships at HF,
especially where they run full duplex telephony. Not that many do these days
in the commercial field, but the military have a lot of experience of these
effects. Somewhere I've a conference paper given some 20 odd years ago from
the UK MoD people on the subject, which told how they traced it on anumber
of ships. I remember them having a problem because in some cases, below a
certain power level it disappeared abruptly.. Fortunately, the
characteristics of tetrodes generally make the transmitter a negligible
contributor, but the external environment is another matter. Worse at sea,
of course because you've got continuous corrosion!
>
> 73
> Peter G3RZP
>
> ------------------------------
>
> Message: 3
> Date: Fri, 07 Sep 2007 09:09:03 +0000
> From: "Johan" <johan.van.de.velde@telenet.be>
> Subject: Re: [Amps] crossmodulation in PA
> To: g3rzp@g3rzp.wanadoo.co.uk, amps@contesting.com
> Message-ID: <W561079561109451189156143@nocme1bl6.telenet-ops.be>
> Content-Type: text/plain; charset="us-ascii"
>
> This might be of interest :
>
> http://www.cabelcon.dk/technic/terms/PIM-english.pdf
>
>
> >----- Oorspronkelijk bericht -----
> >Van: Peter Chadwick [mailto:g3rzp@g3rzp.wanadoo.co.uk]
> >Verzonden: vrijdag, september 7, 2007 10:46 AM
> >Aan: amps@contesting.com
> >Onderwerp: Re: [Amps] crossmodulation in PA
> >
> >Over the years, this has been a well known problem on ships at HF,
especially where they run full duplex telephony. Not that many do these days
in the commercial field, but the military have a lot of experience of these
effects. Somewhere I've a conference paper given some 20 odd years ago from
the UK MoD people on the subject, which told how they traced it on anumber
of ships. I remember them having a problem because in some cases, below a
certain power level it disappeared abruptly.. Fortunately, the
characteristics of tetrodes generally make the transmitter a negligible
contributor, but the external environment is another matter. Worse at sea,
of course because you've got continuous corrosion!
> >
> >73
> >Peter G3RZP
> >_______________________________________________
> >Amps mailing list
> >Amps@contesting.com
> >http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Fri, 7 Sep 2007 11:36:15 +0200
> From: "Nils Petter Pedersen" <la7sl@online.no>
> Subject: Re: [Amps] 7.5V Zener 10W for TL922
> To: <amps@contesting.com>
> Message-ID: <000401c7f132$8a60ffa0$6401a8c0@pcnede>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Hi Aron.
> Maybe this one will fit ?
> 73's Peter
>
http://www.mouser.com/search/ProductDetail.aspx?R=1N2971Bvirtualkey62850000virtualkey898-1N2971B
>
> >
> > HI,
> > Looking for 7,5 v zener 10w diode for TL922.
> > wonder where i can buy them.
> > Thanks,
> > Aron 4x1fq.
> >
> >
>
>
>
> ------------------------------
>
> Message: 5
> Date: Fri, 07 Sep 2007 11:12:31 +0200
> From: w6duv <w6duv@planet.nl>
> Subject: Re: [Amps] QRO or Commander
> To: amps@contesting.com
> Message-ID: <002e01c7f12f$55683c80$6f273f4d@laptopDick>
> Content-Type: text/plain; format=flowed; charset=iso-8859-1;
> reply-type=original
>
> The Emtron DX2 could be a good alternative as well.
>
> Cheers Dick
> PA3DUV
> W6DUV
>
> ----- Original Message -----
> From: "Dino Darling" <dino@k6rix.com>
> To: <amps@contesting.com>
> Sent: Friday, September 07, 2007 6:00 AM
> Subject: Re: [Amps] QRO or Commander
>
>
> > There is a little history between these two companies too. One
> > became two and they split because of differences of opinions. I know
> > for a long time there was info on one of the sites about the split
> > but I would only be guessing at the reason now. It had the
> > appearance of being friendly and only over a difference of company
> > philosophy.
> >
> > Without any name calling or bashing, what IS the correct story?
> >
> > The Command Tech uses Eimac triodes (3CX800A7) and the QRO uses
> > Svetlana Russian tetrodes (4CX800A)
> >
> > Since they spawn from the same egg at one time, my guess is that both
> > sell a quality product. Over time, the QRO will cost less to
> > maintain because of the cost of tubes. The QRO also requires less
> > drive power. But there is something to say about the ruggedness of
> > the Eimac triode. I'd be happy with either one for multiple reasons.
> >
> > Sorry I was of NO HELP!
> >
> > Dino - K6RIX
> >
> >
> > At 12:18 PM 9/6/2007, you wrote:
> >
> >>QRO HF-2500DX vs. Commander HF-2500
> >>
> >>Which would you choose and why? They both appear to be very capable
> >>amps. Are there others you would suggest in this price range?
> >>
> >>Philip
> >>_______________________________________________
> >>Amps mailing list
> >>Amps@contesting.com
> >>http://lists.contesting.com/mailman/listinfo/amps
> >>
> >>
> >>
> >>--
> >>No virus found in this incoming message.
> >>Checked by AVG Free Edition.
> >>Version: 7.5.485 / Virus Database: 269.13.8/993 - Release Date:
> >>9/6/2007 3:18 PM
> >>
> >>
> >>
> >>
> >>--
> >>No virus found in this incoming message.
> >>Checked by AVG.
> >>Version: 7.5.485 / Virus Database: 269.13.8/993 - Release Date: 9/6/2007
> >
> > Dino - K6RIX
> > dino@k6rix.com
> >
> >
> > --
> > No virus found in this outgoing message.
> > Checked by AVG.
> > Version: 7.5.485 / Virus Database: 269.13.8/993 - Release Date: 9/6/2007
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
>
>
> ------------------------------
>
> Message: 6
> Date: Fri, 7 Sep 2007 07:11:41 -0400
> From: "Tom Rauch" <w8ji@contesting.com>
> Subject: Re: [Amps] crossmodulation in PA ? Thanks for all good
> ??advice
> To: "k7fm" <k7fm@teleport.com>, "Nils Petter Pedersen"
> <la7sl@online.no>
> Cc: amps@contesting.com
> Message-ID: <002b01c7f13f$e37c3430$640fa8c0@radioroom>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Hi Colin,
>
> >I mentioned this morning that I had some question about the
> >copper bonding
> > across the tower joints, and raised the question that it
> > could create
> > corrosion. Copper has a .35 volt potential and
> > hot-dip-zinc has a 1.20 volt
> > potential. Even though the tower is bolted together with
> > bolts, there is a
> > process called "fretting" that can cause corrosion to
> > occur between the
> > metals that are otherwise solidly joined.
>
> My point was that with rare exception bonding a tower joint
> is a waste of time. There are tens or hundreds of thousands
> of sheer pressure on the bolts in a typical cross-bolted
> tower joint.
>
> While I agree dissimilar metals should be avoided, placing
> them across a tower joint is meaningless. How good would the
> diode be if it is shorted end-to-end with what we could
> consider a zero ohm connection? The same is true for
> lightning. Lightning doesn't care a bit if the joints are
> bridged or not.
>
> There are some rumors that bonding the joints helps things,
> but they probably came from looking at early broadcast
> towers with pad joints. In many cases those joints would
> have brazed connections jumpering the joint, but in later
> installations that was practice abandoned after it was found
> unnecessary. This probably spawned the idea Hams should
> jumper joints. Anyone who thinks a couple stainless steel
> clamps with a few dozen pounds per square inch clamping
> force will significantly change the connectivity in a joint
> bearing tens of thousands of pounds force probably hasn't
> thought about the system.
>
> It really is meaningless. The possible exception is in
> systems ready to fall down anyway.
>
> 73 Tom
>
>
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Fri, 7 Sep 2007 09:40:42 -0400
> From: Bill Fuqua <wlfuqu00@uky.edu>
> Subject: Re: [Amps] crossmodulation in PA
> To: "g3rzp@g3rzp.wanadoo.co.uk" <g3rzp@g3rzp.wanadoo.co.uk>,
> "amps@contesting.com" <amps@contesting.com>
> Message-ID: <5.1.1.5.2.20070907093805.0376ca40@exchange.uky.edu>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> In the old days military sites had the receiving equipment and antennas a
> few miles away from the transmitting site to avoid a number of problems.
> Naturally receivers those days were easily overloaded by off frequency
> signals.
>
> 73
> Bill wa4lav
>
>
> At 04:46 AM 9/7/2007 -0400, Peter Chadwick wrote:
> >Over the years, this has been a well known problem on ships at HF,
> >especially where they run full duplex telephony. Not that many do these
> >days in the commercial field, but the military have a lot of experience
of
> >these effects. Somewhere I've a conference paper given some 20 odd years
> >ago from the UK MoD people on the subject, which told how they traced it
> >on anumber of ships. I remember them having a problem because in some
> >cases, below a certain power level it disappeared abruptly.. Fortunately,
> >the characteristics of tetrodes generally make the transmitter a
> >negligible contributor, but the external environment is another matter.
> >Worse at sea, of course because you've got continuous corrosion!
> >
> >73
> >Peter G3RZP
> >_______________________________________________
> >Amps mailing list
> >Amps@contesting.com
> >http://lists.contesting.com/mailman/listinfo/amps
>
>
>
> ------------------------------
>
> Message: 8
> Date: Fri, 7 Sep 2007 06:31:37 -0700
> From: "k7fm" <k7fm@teleport.com>
> Subject: Re: [Amps] crossmodulation in PA ? Thanks for all good
> ??advice
> To: "Tom Rauch" <w8ji@contesting.com>, "Nils Petter Pedersen"
> <la7sl@online.no>
> Cc: amps@contesting.com
> Message-ID: <004f01c7f156$97406610$57aef204@colin>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> While I only have sufficient knbowledge on the subject to ask questions,
> logic seems to tell us that "bonding" could be counterproductive. If the
> purpose of bonding is to provide a good ground for lightning, that would
be
> a meaningless act, since lightning is indifferent to less than perfect
> joints. But, if the purpose of the bonding is to provide a zero ohm
> connection, then the only thing that would prevent that is corrosion -
which
> could occur by placing the copper bonding strap at the connection. What
> would start out as a good connection could be made less than perfect by
> corrosion created by the addition of the unnecessary copper bonding strap.
>
> As I understand it, even though the joint has substantial pressure, the
> process of fretting can create corrosion on the surface of the joined
> surfaces - which would then act as a less than perfect conductor despite
the
> pressure. If that occurred, then we no longer have a zero resistance
> connection. That process would not be likely to happen without the copper
> bonding straps.
>
> Colin
>
> "My point was that with rare exception bonding a tower joint
> is a waste of time. There are tens or hundreds of thousands
> of sheer pressure on the bolts in a typical cross-bolted
> tower joint.
>
> While I agree dissimilar metals should be avoided, placing
> them across a tower joint is meaningless. How good would the
> diode be if it is shorted end-to-end with what we could
> consider a zero ohm connection? The same is true for
> lightning. Lightning doesn't care a bit if the joints are
> bridged or not.
>
> There are some rumors that bonding the joints helps things,
> but they probably came from looking at early broadcast
> towers with pad joints. In many cases those joints would
> have brazed connections jumpering the joint, but in later
> installations that was practice abandoned after it was found
> unnecessary. This probably spawned the idea Hams should
> jumper joints. Anyone who thinks a couple stainless steel
> clamps with a few dozen pounds per square inch clamping
> force will significantly change the connectivity in a joint
> bearing tens of thousands of pounds force probably hasn't
> thought about the system.
>
> It really is meaningless. The possible exception is in
> systems ready to fall down anyway."
>
>
>
>
> ------------------------------
>
> Message: 9
> Date: Fri, 7 Sep 2007 10:10:45 -0400
> From: "jeremy-ca" <km1h@jeremy.mv.com>
> Subject: Re: [Amps] crossmodulation in PA
> To: <g3rzp@g3rzp.wanadoo.co.uk>, <amps@contesting.com>, "Bill Fuqua"
> <wlfuqu00@uky.edu>
> Message-ID: <004601c7f159$3d0660c0$6500a8c0@KITTYMA123>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> Aboard USN ships RX and TX antennas were often parallel and only 30-60'
> apart. This was with WW2 and earlier technology. Transmitters were usually
> in the 500 to 2KW input range. TBK, TBM, TBL, FRT were some of the series
> designators.
>
> Shore stations running 5-25+ KW used seperate facilities.
>
> OT's will recognize the RAK/RAL and RBA, RBB, RBC series as especially
> bullet proof.
>
> In the mid 60's transceivers such as the AN/URC-32 began to take over ship
> communication.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Bill Fuqua" <wlfuqu00@uky.edu>
> To: <g3rzp@g3rzp.wanadoo.co.uk>; <amps@contesting.com>
> Sent: Friday, September 07, 2007 9:40 AM
> Subject: Re: [Amps] crossmodulation in PA
>
>
> > In the old days military sites had the receiving equipment and antennas
a
> > few miles away from the transmitting site to avoid a number of problems.
> > Naturally receivers those days were easily overloaded by off frequency
> > signals.
> >
> > 73
> > Bill wa4lav
> >
> >
> > At 04:46 AM 9/7/2007 -0400, Peter Chadwick wrote:
> >>Over the years, this has been a well known problem on ships at HF,
> >>especially where they run full duplex telephony. Not that many do these
> >>days in the commercial field, but the military have a lot of experience
of
> >>these effects. Somewhere I've a conference paper given some 20 odd years
> >>ago from the UK MoD people on the subject, which told how they traced it
> >>on anumber of ships. I remember them having a problem because in some
> >>cases, below a certain power level it disappeared abruptly..
Fortunately,
> >>the characteristics of tetrodes generally make the transmitter a
> >>negligible contributor, but the external environment is another matter.
> >>Worse at sea, of course because you've got continuous corrosion!
> >>
> >>73
> >>Peter G3RZP
> >>_______________________________________________
> >>Amps mailing list
> >>Amps@contesting.com
> >>http://lists.contesting.com/mailman/listinfo/amps
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
>
> ------------------------------
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> End of Amps Digest, Vol 57, Issue 12
> ************************************
>
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