Arthur,
Nice pixs well lit with good detail. If only I had spent some time digging
around that would have been much easier to solder to. May change it the
next time I am in the unit.
I do agree that the reg was running pretty hard but you attached it to at
least a 115 degree heat sink. (At least
I have read about the EFC mod for the 5680A by Bill Riches and adapted
for external by Arthur Dent. Nice work.
Maybe I missed a detail in all the recent messages --
Question:
Has anyone measured or calculated the tuning sensitivity of the pin-5
EFC voltage? (Hz/V number)
I have not but it is sensitive and suspect I actually may have the answer
in my notes.
I was pretty much attempting to range it in to match my operating RB and it
did that quite well. But as I say I suspect I could back out the
sensitivity, maybe.
Regards
Paul
On Sun, Jan 15, 2012 at 8:58 PM, Rex
Just did the pot addition to my FE5086 and it works very well
The systems still warming up and its actually apart with external heat
sinks for cooling so I can get to places.
Hitting 8.6 ^ -12 after first eyeball adjustment on the scope drifting 5 ns
in 9:36 minutes. Time to flip from scope mode
Arthur,
800mW will give you a 52C rise in junction temperature over ambient when not
mounted to anything. The 5680s get pretty hot, probably 50C internally (has
anyone measured it?). That will put you at 102C. Make sure the flavor of
7805 you selected is rated for that (most are rated for
Just one data point: Last night, I taped a thermocouple to the top
case of a unit and read 50C.
Joe Gray
W5JG
On Wed, Jan 11, 2012 at 7:12 AM, Robert Benward rbenw...@verizon.net wrote:
Arthur,
800mW will give you a 52C rise in junction temperature over ambient when not
mounted to anything.
On Mon, 9 Jan 2012 13:06:12 -0800 (PST)
Arthur Dent golgarfrinc...@yahoo.com wrote:
On the inside of the case where the DB-9
pins go through the circuit board, I mounted a 7805 fixed regulator. I
cut a piece out of pin 4 and connected the output of the 7805 to the
board side of the pin
As has been mentioned by Pete and others the majority of the inexpensive
5680 units can only be adjusted for frequency by inputting rs232 info. I am
experimenting with a simple mod to add a fx adjust pot to my unit. I
removed the unconnected dummy pot and glued a miniature 100 k pot upside
down
