In a world of Pi output tanks, I know that the Old School approach of an Inductive Link tank is not cool, but if you look at the original design of those transmitters that’s what they designed them around and keeping this in mind I did
what the old nineteen sixties ARRL Handbook recommended I am just using the output of the link tank with no loading coil directly, will try playing around with series capacity and see if there is anything that can be picked up that way but wanted to keep this
simple with a minimum of modifications. I know most modify the transmitter for cathode keying but wanted to also keep all that original so installed on the rack panel is a high voltage relay that keys the HV on and off for keying the transmitter. Using a choke
input filter and only 8 micro farads yelp is held to a minimum, also have a VR tube regulator on the oscillator feed that helps keep some form of load on the HV supply when not keyed to keep the capacitor of charging way up from the power supply being unloaded.
Because big value capacitors are no longer a big deal everyone now days builds a lot of filter capacity in there HV supplies and think in some ways that adds to the problem of frequency stability when keyed but with this minimal filter find the transmitter
keys just fine and has no detectable AM noise.
There is a lot you can do to make this a better transmitter, but in some ways just like using the old HRO receiver in its original configuration the challenge of doing things working within the confines of original design can be fun.
Have considered ditching coax entirely on this set up and running open wire to an end fed Hertz, at some point want to kick around the idea of a small shed or out building located away from the house, shop and all that with just Old School
radios and an open wire feed system.
Ray F/KA3EKH
From: [email protected] <[email protected]> On Behalf Of
Mark K3MSB via groups.io
Sent: Tuesday, August 8, 2023 6:19 PM
To: [email protected]
Subject: Re: [MMRCG] Giant leap backwards
>> I assume you are using a modified cathode keying with a static T/R switch instead of break in?
Perish the thought! Don't you like that relay clanging away running break in ?
I must admit though, I have thought of putting a reed relay inside the antenna relay to quiet things up....
Mark K3MSB
On Tue, Aug 8, 2023 at 5:14 PM J Mcvey via
groups.io <ac2eu=[email protected]> wrote: