Tsebi Projects Forum

Useful Direwolf configuration information:-

https://ww8tf.club/building-an-aprs-igate/

Candidates for replacement repeater:-

Retuning the Sinclair Q2330E using the aforementioned method yielded better looking curves and better symmetry. The SWR curve, however, still looks messy. TX~ANT.png RX~ANT.png TX~RX.png TXSWR.png Final results: TX insertion loss = 1.47dB (35W input required for 25W output) RX insertion loss = 1.78d...

Improved tuning procedure using only insertion loss measurement:- 1. With a T-connector, tune individual cavities. This can be done with the complete harness in place but only one of the two or three cavities connected at one time for tuning. Doing so saves an extra step (#5). 2. Set the scope cente...

Retuned the Sinclair Q2330E cavity:-

Final results:
TX insertion loss = 1.46dB
RX insertion loss = 1.68dB
TX-RX isolation @145.625MHz = 97.43dB
TX-RX isolation @145.025MHz = 91.24dB
TX SWR = 1.06

Telewave TPRD-1544 retuning results


Final results
TX insertion loss = 2.20dB
RX insertion loss = 2.71dB
TX-RX isolation @145.625MHz = 87.49dBm
TX-RX isolation @145.025MHz = 78.51dBm
TX SWR = 1.18

Potential source for the PLL chip (LMX2352TM):-
https://www.radioparts.com/catalogsearc ... =LMX2352TM

UPDATE: They only have the LMX2306TM and not the LM2352TM

Preliminary findings:- 1. The output VCO is producing a -1.3dBm repeated signal on 200.175MHz to 200.224MHz. The PLL is not locking and the TUNLK signal is not going high. For some reason, the PLL does not appear to be working. 2. Post TXVCO amplifier chain voltages appear to be correct. 3. 15.3MHz...

Testing preliminaries:- 1. Check quiescent RX current before lockup 2. Check current during TX lockup 3. Check if there is RF output during brief PTT with beep 4. Check if there is RF output during TX lockup 5. Assuming T8V is present, check Q38 collector voltage to ensure that driver stage is still...

Schematics of TX-RF amplifier stage:-
Source for RA60H1317M:-

https://www.rfparts.com/catalogsearch/r ... ra60h1317m
https://www.radioparts.com/icom-1150002073