+--------------------------------+------------------------+-----------------------------+------------------------------------+
|        Level of extension      |   Ordinary extension   |     Reception extension     |   Transmission/Reception extension |
+--------------------------------+------------+-----------+-----------------------------+------------------------------------+
|  Modification                  |Cut b0 (JP1)| Delete b1 | Delete a6 (&24,R21, and R20)| Delete a6 (R24) and R21 (width R20)|
+------------------+-------------+------------+-----------+---------------+-------------+------------------------------------+
|                  | Destination |      K     |    W      |       K       |      W      |           All destinations         |
|     Label        +-------------+------------+-----------+---------------+-------------+------------------------------------+
|                  | Transmission| 400 ~ 470  | 400 ~ 470 |   400 ~ 470   |  430 ~ 440  |              400 ~ 500             |
|                  | Reception   | 400 ~ 470  | 400 ~ 470 |   400 ~ 500   |  400 ~ 500  |              400 ~ 500             |
+------------------+-------------+------------+-----------+---------------+-------------+------------------------------------+
| Guide values of  | Transmission| 405 ~ 460  | 405 ~ 460 |   405 ~ 460   |  430 ~ 440  |              405 ~ 460             |
| PLL lock ranges* | Reception   | 405 ~ 460  | 405 ~ 460 |   405 ~ 460   |  405 ~ 460  |              405 ~ 460             |
+------------------+-------------+------------+-----------+---------------+-------------+------------------------------------+

* The PLL lock ranges are guide values. Unstable operation my occur around the upper/lower limits of frequency. For use at frequencies around the upper/lower limits of the lock range or soutside the lock range, readjust the lock range.

Adjusting the lock range:

TX-RX unit X57-3520-21. VCO coil L1 (Common transmission/reception.)

Note from www.mods.dk: Under the table "Reception/Modification" the label "Delete a6 (&24,R21, and R20)", i'm not sure about the text "&24", maybe the "&" character is another character. It was a very bad picture i have to read from. Mail me if you have any changes