Search found 182 matches

by DanubeBCL
Sun Jul 02, 2017 10:00 am
Forum: SDR Antennas
Topic: Bias T and active mini-whip
Replies: 15
Views: 4105

Re: Bias T and active mini-whip

Paul, with a power consumption of 100 ... 150 mA nothing should overheat. Either you have a (sporadic or permanent) short circuit or an interruption on the power supply line somewhere or there is indeed something wrong in the whip. Do you have an Amp/Ohm/Voltmeter to make measurements on the equipme...
by DanubeBCL
Sun Jul 02, 2017 7:40 am
Forum: SDR Antennas
Topic: Bias T and active mini-whip
Replies: 15
Views: 4105

Re: Bias T and active mini-whip

Heinrich - I've just checked the noise on the Antenna B input with the bias-T enabled/disabled. I can detect nothing, even with the scope on 5mV with a x1 probe. Clean as a whistle. Of course, this may just mean my particular laptop is clean! OK, that's better than the Funcube. I just fetched my Fu...
by DanubeBCL
Sat Jul 01, 2017 8:37 am
Forum: SDR Antennas
Topic: Bias T and active mini-whip
Replies: 15
Views: 4105

Re: Bias T and active mini-whip

A question in this context (I do not own an RSP2): Is the bias T voltage of the RSP2 "clean"? I have a Funcube pro+ and it's bias T is a horror. It can only (if ever) be used for VHF and above. Below is carries extreme USB noise and noise from the 5 V USB line. I have applied extra SMD cap...
by DanubeBCL
Fri Jun 30, 2017 6:44 am
Forum: SDRplay related
Topic: RSP2 LO 3rd harmonic spurious response only -20dBC
Replies: 17
Views: 4142

Re: RSP2 LO 3rd harmonic spurious response only -20dBC

I think what Juha wanted to say is that they shoud have provided low pass filters behind the LO. My opinion: When someone expects high standards of a spectrum analyzer or monitoring receiver shouldn't he go better for a Rhode & Schwarz FSW8/FSW13 https://www.rohde-schwarz.com/us/product/fsw-prod...
by DanubeBCL
Thu Jun 29, 2017 8:06 am
Forum: SDR Antennas
Topic: Long Wire Antenna Performance Questions
Replies: 7
Views: 3248

Re: Long Wire Antenna Performance Questions

When you only have room for 3 m poles you should inform yourselves about EWE antennas. There are many sources on the web, this one I just picked by chance: http://www.radiodx.com/articles/technical/antennas/it-had-to-be-ewe/ But EWEs are directional and work best for MW and lower SW bands. Have you ...
by DanubeBCL
Thu Jun 29, 2017 7:03 am
Forum: SDR Antennas
Topic: Long Wire Antenna Performance Questions
Replies: 7
Views: 3248

Re: Long Wire Antenna Performance Questions

Can you please share some details? 1. height of metallic pole : 8 metres, base connected to ground rods, coaxial cable also grounded at the foot of the mast 2. height of wooden pole: appr. 14 m (a tree ;-) ) 3. turns and core for the two 1:1 balun: Appr. 30 turns of RG 178 coax. cable on an FT 140-...
by DanubeBCL
Thu Jun 29, 2017 6:33 am
Forum: SDRplay related
Topic: SDRplay_HDSDR download issues viruswarning
Replies: 6
Views: 1609

Re: SDRplay_HDSDR download issues viruswarning

That's always the same story. Some virus scanners do a superficial job and are programmed sloppy. Indeed currently 6 anti-virus engines rate SDRplay_HDSDR_Installer_2.76_2.exe as an evil software. This is about the same hit rate as for software 4.1 for the well known Perseus SDR. The superficial &qu...
by DanubeBCL
Mon Jun 26, 2017 8:16 am
Forum: SDR Antennas
Topic: Long Wire Antenna Performance Questions
Replies: 7
Views: 3248

Re: Long Wire Antenna Performance Questions

When reading your message I was totally confused which "wires" you did connect to what. But I try to visualize what you did. 1) What is the balun doing that suppresses BC AM overload? When your balun (which is in fact an unun for a longwire) suppresses overload it must be connected wrong. ...
by DanubeBCL
Sun Jun 25, 2017 5:50 pm
Forum: SDR Antennas
Topic: RA0SMS Miniwhip bad performance on SDRPlay
Replies: 31
Views: 13596

Re: RA0SMS Miniwhip bad performance on SDRPlay

This PS was a short time ago sold here in Germany under the label "Voltcraft". This Chinese PS has various names around the world. The term "linear adjustable" is misleading. It is a switched PS! In this German blog someone has dismantled the unit. It is not necessary to understa...
by DanubeBCL
Sun Jun 25, 2017 7:40 am
Forum: SDR Antennas
Topic: RA0SMS Miniwhip bad performance on SDRPlay
Replies: 31
Views: 13596

Re: RA0SMS Miniwhip bad performance on SDRPlay

All three wallplugs seem to be overchallanged for me. They have no or little headroom. Maybe the 100 mA type could work. But all three seem to be switched types and especially in the vicinity of an E field antenna (like the whip) RF noise must be taken into account. From the label alone you cannot s...

Go to advanced search