Re: Reception -- Point Blank FM Message Board

[ Show ]

Support VoyForums

[ Shrink ]

VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

[ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 1 ]

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: 16:19:28 04/30/03 Wed
Author: Point Blank Engineering
Author Host/IP: user-932.bbd22tcl.dsl.pol.co.uk / 81.77.235.164
Subject:

Re: Reception
In reply to: Paul 's message, "Re: Reception" on 12:02:29 04/29/03 Tue

mmm...I see, well power wise there is a drop of 50 watts from christmas time. We are using a double stack right now which sems to be working rather well.

The mains hum is a pain in the arse, the switched mode supply for the transmitter is picking up rf through the mains. So we de-coupled it and the noise dropped by over half but it is still there. Gonna try 2 ferrite rings on the supply right before the switcher......

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Replies:

[> [> [> Re: Reception -- Paul, 19:13:20 05/01/03 Thu (pc-80-194-114-133-hy.blueyonder.co.uk/80.194.114.133)

The ferrite rings sound like a good idea. Why not go one step further and put a proper rf filter right on the mains i/p as it comes into the box, just a single L-C pi section or something similar? Are you sure the rf's getting in at the input? Might actually be around the switching device itself; of course, if you're using a decent well screened box then I'm sure this isn't the problem!

Big up the double stack! Have you ever tried a J? Not a slim-jim, a proper J i.e. 1/2 wavelength radiator at the top and 1/4 wave matching section at the bottom. Gain figure on paper is not as impressive as a double stack but much lower angle of radiation, easier to set-up and also far less obvious than a double stack on top of the block!

I'll be listening for the mains hum this weekend!

Paul, Ruislip

[ Post a Reply to This Message ]
[ Edit | View ]