[R-390] PIN Diode question resolved(?)

[Perry Sandeen]

GM List,

Thanks to all who responded about my question if it was feasible to use PIN diodes for tap selection on a loop antenna.

My original quest was based on a circuit from  Ulrich Rhode’s book  “Communication receivers: principles & design” which had a HP PIN diode attenuator circuit for HF. (It is figure 5.21 on page 239.)  I figured if it could work for him, why not me? Ah ass-u-me!

The general consensus is that they will not work at low frequencies. There maybe an exception with the 1N007 (only) diode due some different doping than the other 1N400X series.  At least it will be cheap to try.

Several suggested relays. I had thought of that but the cost of $3 + stated making this a very expensive project.  What I finally came up to try was to buy some cheap surplus latching relays on epay.

Unfortunately at the moment I don’t have the time to build my loop. 

Those interested in building loop antenna just need to do a google search.  There are more articles than you could shake a stick at, including at least tow that will do all the calculating of frequency ranges once you enter you design parameters.

Regards,

Perrier