3000A-series 200MHz board to 500MHz board upgrade how-to.Similar procedure can be applied to 3000T and 4000A series.
To extend 100/200MHz board to 350/500MHz you'll need to perform serious hardware modification of the main board.
Decent SMD soldering skill and soldering equipment are required to perform this modification.
Thus, it's not recommended to try this mod unless you're really desperate to get extra bandwidth.
This is a description of hardware modifications on sensitive signal paths of the scope!Applying any of these mods will void your warranty and calibration!Loss of factory calibration and accuracy is inevitable!DISCLAIMER: do this at your own risk only! Irreversible damage may be caused by these modifications. You've been warned!Required materials for 4-channel models:
1. Coilcraft 0603CS-15NXG 0603 15nH 2% inductors - 12 pcs
2. Coilcraft 0603CS-27NXG 0603 27nH 2% inductors - 4 pcs
3. 0603 2.2pF NP0 capacitors - 4 pcs
4. 0603 2.0pF NP0 capacitors - 4 pcs
5. 1206 110R 1% resistor - 4 pcs
6. 0603 162R 1% resistor - 4 pcs
7. 0603 121K 1% resistor - 1 pcs
8. 0603 46.4K 1% resistor - 1 pcs
User cal fixture is required for post-modification calibration.
BACKUP NOTE: save all removed components in separate places for each position and channel to secure way back to original values!Modification process (see attachments for pictures):
1. For each channel replace yellow-marked parts as follows:
AFE top layer (afe_top_layer_mod.jpg):
L1: 100nH(?) ->
15nHR1: 215R ->
110RL2, L3: 47nH(?) ->
15nHC1: 4.7pF ->
2.2pFC2: 4.7pF ->
2.0pFAFE bottom layer (afe_bot_layer_mod.jpg):
L4: 100nH(?) ->
27nHR2: 261R ->
162R2. Replace two board strap resistors:
Top layer near CPU (gnd_straps.jpg):
Strap resistor L1: 10K ->
46.4KBottom layer under CPU (2v5_straps.jpg):
Strap resistor H1: 100K ->
121KNOTE: all capacitor values are guessed or measured and may not be 100% correct.
Run a brief per channel check of scope functionality before fully reassembling the scope. For a final assembly be sure to mount all shields and covers. Run User cal procedure with a high-quality user cal fixture to compensate replacement of AFE components.
Done, you'll get a 350MHz scope. 350MHz to 500MHz upgrade is software-only and possibly discussed elsewhere.
I'd like to thank all eevblog members who contributed to this mod with their knowledge and time and did measurements on their scopes.
This wouldn't be possible without their kind help.