Assembly notes
All files (C) David Wrigley - 2001 Oct 07

Files list
20020130-Hittite-prescaler-01c assy.bmp   component assembly to PCB
20020130-Hittite-prescaler-01c-rev-art.bmp  mirror image for "iron-on" PCB manufacture
200110070001b.jpg  photo of completed prototype assy in tinplate enclosure
20020130-assy notes.txt   these notes
200110070045b.jpg  showing the use of the prescaler with a Watson freq counter and waveguide transition.  It is quite sensitive.
200110070103b.jpg  photo of rear of pcb showing the PSU arrangement.

PCB
The copper track image enclosed is a mirror image ready for the iron-on process after printing out on laser printer. Alternatively (as I do) you could print out on an ink-jet and then use a laser copier at your local copy shop.
If you wish to make a negative for a more conventional process - just mirror the image prior to use.

Component assy:
To fit the ERA-3,
Drill a hole to allow the body of the device to drop down thru the pcb
so the leads are level with the tracks
Snip off the leads to make them about 1mm long
Fit "u" shaped copper strips thru the hole to connect the ground pads to the back plane
Then fit the device, white dot/angled lead is input.  I used silver loaded solder paste

To fit the Hittite prescaler
Put a small blob of solder/solder paste under the device and align it.
Solder one corner lead to its pad to locate the device
Apply heat to the adjacent ground pad to melt the solder under the device
Ensure that it has settled down on the ground pad before removing heat.
(I applied heat alternately each end to ensure that it was firmly stuck.)
Solder the rest of the leads to the pads.

When you're testing it, just apply a finger (grounded, of course) to the top of the package to check the temperature - if it feels hot - it probably isn't grounded properly. It will be dissipating around 360mW and the ground pad will be a useful mechanism for dissipating the heat. 

To fit the PSU components.
A lead thru cap of 1nF or greater goes thru a hole in the side of the case (I used a 7nF which was marked 5nF)
A series diode is fitted to prevent damage by power reversal
A 7805 regulator soldered to the tinplate case - It dissipates about 0.67 W when driven from 12Volts - the case will cope with this - it just gets warm after a while.
A 1uF SMD Tantalum capacitor was fitted across the regulator input terminals to allow for the possibility of long supply leads.
All these compoments can be seen in the photo.

