Date: Sun, 12 May 2019 18:55:59 +0100
From: Chris Wilson <dead.fets@gmail.com>
Message-ID: <32324606.20190512185559@gmail.com>
To: rsgb_lf_group@blacksheep.org
In-Reply-To: <1UTJHsWaAT.3NHw5CM2m0M@optiplex980-pc>
References: <336545566.20190511184405@gmail.com> <1UTJHp87NM.2LemuKEGHv@optiplex980-pc> <475810047.20190512125038@gmail.com> <1UTJHsWaAT.3NHw5CM2m0M@optiplex980-pc>
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Subject: Re: LF: Re: MF amp
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Hello Jay,

Just sent an e-mail direct to jrusgrove@comcast.net and this is a reply
to your Blacksheep post.

BTW, with regard to measuring the voltage across the stacked caps to
ground on the centre tap of the transformer on your MF amp, I am
looking for minimum voltage, correct? Thanks!

Sunday, May 12, 2019, 5:18:12 PM, you wrote:

> Chris

> Don't think the problem is on this end as your's is the one and
> only e mail where the reply to fills in an unexpected, Blacksheep, e
> mail address. Perhaps you replied to an earlier Blacksheep reflected
> e mail of mine and 'harvested' my e mail address to use in the To:
> box? That may be very different than starting a new 'clean slate' e
> mail in your e mail client and typing in my e mail address from
> scratch or doing a copy and paste. Suggest sending me a 'clean
> slate' e mail as a test to see if this explains the unusual behavior.

> Jay W1VD       

> ----- Original Message -----
> From: Chris Wilson <dead.fets@gmail.com>
> Reply-To: <rsgb_lf_group@blacksheep.org>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: 5/12/2019 7:50:38 AM
> Subject: Re: LF: Re: MF amp
> ________________________________________________________________________________


> Hello  Jay,  understood  re short probe ground and cap values, thanks.
> BTW,  mail  direct to you is still being replied to via Blacksheep! So
> something  is  amiss  with  your mail filtering perhaps? Thanks again,
> have a good weekend.

> Sunday, May 12, 2019, 12:16:52 PM, you wrote:

>> Chris

>> Sorry for slow reply ... been having intermittant e mail problems.

>> The value is not critical. What is required is a good ground at
>> that point. Whatever combination of capacitors  works best is what
>> you want to go with. No doubt this will vary from layout to layout
>> and capacitor type to capacitor type. Use a scope to monitor voltage
>> across the capacitors. Don't use the scope probe ground lead or hook
>> clip as this will not give an accurate reading of what's going on.
>> Instead, remove the hook clip assembly and fashion a piece of #14
>> bare copper wire with several turns and a pigtail. The turns should
>> be sized to fit tightly over the scope probe ground sleeve. The
>> short pigtail can be temporarily soldered to the circuit board such
>> that the 1/4" scope tip comes in contact with the capacitor. The
>> idea is to keep the scope leads as short as possible.

>> Jay


>> ----- Original Message -----
>> From: Chris Wilson <dead.fets@gmail.com>
>> Reply-To: <rsgb_lf_group@blacksheep.org>
>> To: <jrusgrove@comcast.net>
>> Sent: 5/11/2019 1:44:05 PM
>> Subject: MF amp
>> ________________________________________________________________________________


>> Hi Jay,

>> Sorry to be a pain, nearly finished the 1kW MF amp of your design,
>> please clarify if the center tap transformer to ground cap stack needs
>> to be exactly 0.56 uF, or if it's a typo and needs to be only 0.5 uF,
>> what's confusing me is where it states stacking just 0.1 uF MLC
>> chips... Thanks :)

>>   


-- 
Best regards,
 Chris                            mailto:dead.fets@gmail.com