I'm pretty sure the only caps you need to change are those low ESR types on
A9. Just look at the spec sheet, choose low ESR, up the working voltage by
1.5 times the original, buy quality (Nichicon, Panasonic, Kemet, Vishay,
AVX, Rubycon, etc).
Minimize ESR:
https://www.avnet.com/wps/portal/abacus/resources/article/understanding-esr-in-electrolytic-capacitors/
; the article mentions another technique to reduce ESR, which is to
parallel two caps to get your required C value.
Generally, the ceramic caps are OK, as are the tantalums (unless they were
from that particular bad batch at the time).
Summary, replace with:
1) Lower ESR
2) Higher Working Voltage by a factor of at least 1.5
3) Maybe slightly (< 10%) higher Capacitance -- but don't go crazy, unless
you analyze / simulate the circuits and make sure it'd work.
--------
Years ago, I built a small accessory for Panasonic, and put some 10V caps
on a 5V rail, and got raked over the coals by Japanese engineers because,
why wasn't that a 16V cap on the 5V rail? Was I an imbecile who did not
know that the rule at Panasonic was WV >= 3X actual circuit voltage? I
definitely fixed that in the release model. Also, these days, I try buy
Panasonic electronic stuff, because if they pay that much attention to
detail...
Mike K6THZ
On Fri, Dec 30, 2022 at 10:48 AM Byron Cordes via TenTec <
tentec@contesting.com> wrote:
> Be sure to replace those caps with good ones . I buy from Mouser when I
> want good stuff . Not saying it is but I think I have a better chance. I
> also get 10 at a time . Somebody seems in need of a good cap almost every
> month or two around here .
> 73s Byron AC9PA
>
> On Dec 30, 2022, at 11:39 AM, Scott Sheppard <scott.vy1co@gmail.com>
> wrote:
>
> Thanks Marcus
>
> I think for certain it's associated to what you are suggesting...I had
> earlier dropped a note to the radiosmith, steve, who kindly replied he had
> seen that issue in an Orion, but not yet on a O2. He too said to check the
> Voltages going into the tcxo-- which I did...they are bang on by 'my'
> measurements.
>
> The A9 in this rig is a replacement board but still has the smaller caps. I
> plan to replace those as soon as I get the parts...it needs to be done
> anyway.
>
> Thank you for taking the time to reply.
>
> Happy New Year
>
> Scott. Vy1co
>
> On Fri., Dec. 30, 2022, 10:00 a.m. , <tentec-request@contesting.com>
> wrote:
>
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> > Today's Topics:
> >
> > 1. Re: Orion 2 100hz off (Marcus Florido)
> >
> >
> > ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Fri, 30 Dec 2022 11:08:34 +0000
> > From: Marcus Florido <k4vbb@LIVE.COM>
> > To: "tentec@contesting.com" <tentec@contesting.com>
> > Subject: Re: [TenTec] Orion 2 100hz off
> > Message-ID:
> > <
> >
> CY4PR13MB122323FC0ADE608E2C1788258AF09@CY4PR13MB1223.namprd13.prod.outlook.com
> >>
> >
> > Content-Type: text/plain; charset="utf-8"
> >
> > These things drift over time, but I can't imagine that it drifted THAT
> > much. The first thing I would do is to measure the input voltage to the
> > TCXO. Make sure it's at spec. Problem is, I don't know what that
> voltage
> > should be, and the A10 board schematic doesn't appear to have that
> > information readily available. The TCXO appears to be run by a 74AC00
> NAND
> > gate chip. Someone with more knowledge in this area "may" be able to
> > extrapolate what that voltage should be from the datasheet (
> > https://www.onsemi.com/pdf/datasheet/74act00-d.pdf) and the schematic.
> > Knowing the "REF EN" voltage supplying the NAND gate would likely help,
> and
> > someone with more patience than I have could likely follow this back and
> > find out.
> >
> > What I can say is that rebuilding the A9 board solved a myriad of
> oddities
> > with my rig. It is entirely possible that a re-cap of that board might
> > solve your problem, since that board is responsible for providing stable
> > power to the rest of the rig.
> > 74ACT000 - Quad 2-Input NAND Gate - Onsemi<
> > https://www.onsemi.com/pdf/datasheet/74act00-d.pdf>
> > 74AC00, 74ACT00 www.onsemi.com 3 DC ELECTRICAL CHARACTERISTICS FOR AC
> > Symbol Parameter V CC (V) Conditions T A = +25?C T A = ?40?C to +85?C
> Typ.
> > Guaranteed Limits Unit VIH Minimum HIGH Level Input Voltage 3.0 VOUT =
> 0.1
> > V or VCC ? 0.1 V 1.5 2.1 2.1 V 4.5 2.25 3.15 3.15
> > www.onsemi.com
> >
> > ________________________________
> > From: TenTec <tentec-bounces+k4vbb=live.com@contesting.com> on behalf of
> > Scott Sheppard <scott.vy1co@gmail.com>
> > Sent: Monday, December 26, 2022 6:55 PM
> > To: tentec@contesting.com <tentec@contesting.com>
> > Subject: [TenTec] Orion 2 100hz off
> >
> > Hello everyone, and happy holidays.
> >
> > I have a new to me Orion 2 that runs very well, albeit 100 off Freq.
> >
> > I have read the information on the tcxo, but it seems there is no
> > adjustment left in it.. that is to say, it's set at the best position and
> > movement turning either way only increases the problem.
> >
> > I would appreciate it if anyone has some alternative solutions I could
> try.
> > It's not the end of the world, but it would be nice to zero it in. ...I
> > remember having an Omni V with the N4PY v.2 chip...that was brilliant as
> it
> > let you simply adjust the display to correct for crystal aging...
> >
> > 73 to all.
> >
> > Scott. Vy1co
> > _______________________________________________
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> > TenTec@contesting.com
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> > ------------------------------
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> > End of TenTec Digest, Vol 240, Issue 10
> > ***************************************
> >
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