[AMRadio] Parasitic Suppressors (or lack thereof) in the Olden

Geoff/W5OMR ars.w5omr at gmail.com
Wed Apr 11 20:30:26 EDT 2007

ne1s wrote:
> Olden Days being pre-WWII, that is.
> I've noticed most (if not all) if the PP-triode RF PAs of that period 
> don't show the use of any parasitic suppressors in the grid or plate 
> leads. Also a deck I have (exact vintage unknown) using PP triodes 
> doesn't include them.
> How did they get away with this?
there wasn't TV, or VHF at the time.  Don't think we'd pioneered our way 
that far north on the spectrum by that point.

> I've never put power to the above-mentioned deck, but have another one 
> where I tried to follow the same practice (I just used copper strap 
> for the plate leads) and I appear to have an intermittent parasitic, 
> so will be incorporating some suppressors in the plate leads.
> -Larry/NE1S

In my opinion, every T-368, BC-610 and any other rig that does -not- 
have any sort of VHF parasitic choke suppression, needs to be 
retrofitted.  If, for no other reason, than to exhibit 'good engineering 
practices', and further help to eliminate stray RFI into devices that 
act improperly as radio receivers.

W5OMR (/5 New Orleans)

More information about the AMRadio mailing list

This page last updated 21 Jan 2018.