Modifying a 11 metre amp I'm after modifying a 11 metre amp to work on 6 metres, you may not think at first that 6m can be freebanded, but it can UK allocation is only 50-52 mhz, but most of the rest of the world and certainly the US have 50-54 mhz. Many operators freeband the 52+mhz and some also go down to 48 mhz
I have a 6m radio but its QRP and could do with just a bit more power. Whats the criteria on a solid state amp for operating on a particular band?
Re: Modifying a 11 metre amp reckon just a slight re-tuhe.
give me a call on 49.860, or any freq locally thats not swamped by baby alarms and i reckon we could have a qso!!!
--- If it Aint broke, don't fix it, and if you do, don't tell anyone you touched it
Re: Modifying a 11 metre amp It's possible that a valve unit would be simpler to modify than a solid state one. A BRL200 might be a good choice.
You will have to re-wind the tank coil using fewer turns, and the same for the input circuit - trial and error here, along with a bit of common sense. Not done this, but it's simple enough in theory.
One issue you may have is the capacitance of the ouput valves being too high to be able to bring the tank circuit to resonance, in which case disconnect one of the valves at the anode cap and try again.
Re: Modifying a 11 metre amp I have'nt had time for this yet, it is a valve amp a single valve produces about 80w with 4 w drive on 11m.
I'm waiting for the 6m loop antenna I've bought from Moonraker to arrive as well, I only have the home made dipole up for 6m and its pants, mind you 6m is deader than 11m atm
Re: Modifying a 11 metre amp I think you'll have problems with the big valves getting them resonant Dave, the beam tube type shouldn't be an issue though, Tranys will be easier just bypass or retune the pass filter. Watch out for parasitic oscillation wich will obviously keep it driving when unkeyed, I had to reposition the whole pcb to get rid of them thus shortening all the wiring. Its not too bad to do just go slow and deliberate. 519's and 509's work well as do 811's, but i had a sod of a job on a 3-500z amp ended up with over 30 decoupling caps in it!! John193
UK allocation is only 50-52 mhz, but most of the rest of the world and certainly the US have 50-54 mhz. Many operators freeband the 52+mhz and some also go down to 48 mhz 
