Re: Re: LF: MF/160

[Andy Talbot <andy.g4jnt@gmail.com>]

Its a difficult call - I have a similar problem with my 700 Watt 137kHz Tx.   30dB hum sidebands corresponds to 3% ripple, which in the main scheme of things is not that much.   It would need an enormous reservoir capacitor to make a serious reduction.  

Either that or design the Tx to run from 50V and use a SMPSU instead of raw rectified AC

Andy  G4JNT

On 23 October 2017 at 10:03, dhchurch <dhchurch@lineone.net> wrote:

Mal, I think a little attention should be paid to, perhaps, your power supply. The 100Hz sidebands, as I recall from earlier this week, should be much lower in level. Seen on Spectrum Lab at one stage, they were less than -30dB in comparative level. 

 

73, Hugh, M0DSZ

 

----- Receiving the following content -----

From: Andy Talbot

Receiver: rsgb_lf_group

Time: 2017-10-22, 22:44:59

Subject: Re: LF: MF/160

You're so strong, Mal,　 I'm getting decodes on your hum sidebands

21:36　　G3KEV　　0.475804　　-27　　0　　IO94sh　　5　　G4JNT　　IO90iv　　384　　189　　2017-10-22 21:36　　G3KEV　　0.475704　　+3　　0　　IO94sh　　5　　G4JNT　　IO90iv　　384　　189　　2017-10-22 21:36　　G3KEV　　0.475604　　-29　　0　　IO94sh　　5　　G4JNT　　IO90iv　　384　　189　　2017-10-22 1

Andy　 　G4JNT

On 22 October 2017 at 19:25, mal hamilton <g3kevmal@talktalk.net> wrote:

NICE CONDX 160M THIS EVENING VK7DIK 　REPORTING G3KEV WSPR MODE

LOOKING GOOD FOR MF/630 M ALSO

TNX REPORT DE MAL/G3KEV

　

　

　

　

　

　

　

　

　

　

　

　

　

　

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