Hi All, I need to come up with a CLEAN 50W-70W IPA to drive my newly built 6 meter 8877. I have 20W available from a DownEast 50-28 transverter. An older N4NTA 6M kit using a single MRF-492 (10W to 1
BTW, Used as an IPA: Is it possible to clean up the N4LTA 6M MRF-492 brick by idling it at several amps (instead of 100ma) - closer to class A1 and adding some negative feedback via an emitter resist
If you want a nice, linear, driver don't waste time with 12V transistors. 28 or 50V makes a world of difference. Something like MRF173 or MRF150 (fets) from RF Parts won't break the bank but will be
On Mon, 29 Nov 2004 16:05:00 -0500 "Tom Cathey" <k1jj@comcast.net> writes: Hi Tom, You really need something with at least 10dB better IMD numbers, if you wish take full advantage of the 8877's specs
Hi Marv, Your idea about using a 4CX350J IPA is interesting. I suppose it would have to be VERY physically close to the 8877 or the RF negative feedback will have phase shift problems. ie, It will no
Probably easier to bypass it, or run at 100s mW max output so it's in class A. A modern FET will give you 20+dB gain at 50MHz, so 60W out will mean 0.5W or less input. For comparison, we ran a 2m con
On Tue, 30 Nov 2004 14:06:37 -0500 "Tom Cathey" <k1jj@comcast.net> writes: Hi Tom, have will with a Yep... 20° per foot at 6M. Any of those parts are expensive new. I've seen a number of pulls go
Hi Tom, Another interesting idea was about using a ~200W triode and letting it idle in class A1, giving maybe 60W output without worrying about neg feedback. Maybe that would approach -40 db, or perh
Tom... IMD in almost all linear amplifiers follows the 3:1 rule...for a 1 dB increase in power output, the _absolute_ IMD levels increase by 3 dB. This rule is so reliable that it forms the basis of
I didn't see this on the list, so here it is again. Tom: did you get the original? ...or did my email mess up? jeff, wa1hco jeff millar wrote: Tom... IMD in almost all linear amplifiers follows the 3