Hi Peter, I'm using a mains filter (similar to this: http://www.amateurfunkbasteln.de/netzfilter/index.html). The power supply is a conventional transformer (5VA, 15V) + a bridge rectifier + 100uF +
Peter, It's a known problem also here. There are several ways to prevent that noise slip into the DC feederlines. Assume that every situation will be different for each of us, depending the source of
Hello Roelof, VLF, LF, but also HF, VHF, UHF and SHF :-) Today I will try to ad some stabilyzers, filters, C's and Choces at the powers supply Mini Whip input. That single 9 volt battery block was em
Thanks Roelof, I use a lot of 2n5109's and am always on the look out for suitable surface mount devices that might make a good substitute. I will have to get a few of each and give them a try. cheers
Hello Peter, I found that a BFQ19S gives slight better strong signal handling performance. But more important, it works better at a lower supply voltage. So, for use with a 9V battery, the BFQ19S is
Hello Jan, Tnx for your information. I tried already several way's of powering the Mini Whip, but only a battery is clean. All others who are connected to 230 volt mains give noise or QRM. I'll conti
A quick search finds BFQ19 and BFQ19S with different specs. Can a BFQ19 be substituted for a BFQ19S or are they very different? cheers, Graham ve3gtc I found that a BFQ19S gives slight better strong
Hello Graham, A quick search revealed a difference in maximum collector current; 100 mA for the BFQ19 and 75 mA for the BFQ19S. In this application the collector current is about 35 mA at 12V, so wel
Hello Peter, Some power supplies are particular noisy. I use a wall wart type with a transformer (no switching type). But again as you found out, noise differs from one model to the other. It is a pi
A trivial idea: use 2 * 7 A/h battery , one in use, the other under charge .. every 24 hours a 555 timer and a relais switch between the two battery .. I plan to use this arrangement .. 73 Mauro IK1W
Hello Roelof, U use the 2N5109 like you suggested :-) Also that J310 Fet. Also the 470 uH chokes. I did try to keep it orginal as you did designed it. Also PCB is the same (90 x 30 totaly and 45 x 30
