Path: ...!weretis.net!feeder9.news.weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: piglet Newsgroups: sci.electronics.design Subject: Re: Distorted Sine Wave Date: Sat, 1 Jun 2024 22:00:58 -0000 (UTC) Organization: A noiseless patient Spider Lines: 35 Message-ID: References: <3lcf5jd7li0a3c0fgddt7o8lnfocvls2pr@4ax.com> <48bd78e1-7da8-3bba-2879-d22962203fa3@electrooptical.net> <9olh5j9al34fhrebr4grqq8h6c8javjpp1@4ax.com> <1n0i5jh257hiinlj2dhaatlo11s33m5n0e@4ax.com> <9k2i5jpfhu3ncfpm28ukusrok4hugal80s@4ax.com> <9tok5j9p388ookujrtbsofskjlbekfuhjb@4ax.com> <60rk5jti9l5154hqaqicohmj3u1lfd16g3@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Sun, 02 Jun 2024 00:00:58 +0200 (CEST) Injection-Info: dont-email.me; posting-host="8bced55ca9cb076760c6695d7a4bf9db"; logging-data="3146534"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+iAHii3ZfW8qp9XUSGdeAz" User-Agent: NewsTap/5.5 (iPhone/iPod Touch) Cancel-Lock: sha1:Layfk7bWNsKqaL8xQWFxgoPcuAU= sha1:wIz09R2b0DnOfKRR97gTq7tcdoo= Bytes: 2971 Cursitor Doom wrote: > On Sat, 1 Jun 2024 15:44:17 +0200, Jeroen Belleman wrote: > >> On 6/1/24 14:07, Cursitor Doom wrote: > >>> I've taken a shot of the waveform into the 50 ohm input. It's around >>> 850mV peak-peak. Hopefully the slight distortion I spoke about is >>> visible; the slightly more leisurely negative-going excursions WRT >>> their positive-going counterparts. So it's not a pure sine wave as one >>> would expect. Does it matter? I don't know! >>> >>> https://disk.yandex.com/i/7cuuBimDbOIBZw >> >> The shape looks perfectly acceptable to me. This is +3dBm into 50 Ohms. >> Is that what it's supposed to be? Canned reference oscillators most >> often deliver +13dBm, sometimes +10dBm. > > Is it? I only make it about half your figure: +1.65dBm. > I admit I'm frequently prone to careless errors, so stand to be corrected, > but here's my method: > 850mV peak to peak is 425mV peak voltage. Average of that is 0.425x0.636 = > 0.27V. Average power is average volts squared divided by the load > impedance of 50 ohms = 1.46mW = +1.65dBm. > > I shall consult the manual to see what it ought to be - if I can find it, > that is, as PDF manuals are a nightmare to navigate IME. > > Use 0.71 for RMS instead of 0.636 ! I make that about 1.8mW or +2.6dBm ? -- piglet