PA0O ham radio

To finish the long story about repairing The 465 is working fine now I found a solution to prevent damage by possible CRT HV flash over I just inserted a protective 860k resistor ( could be 1M ) in series with the -2450V  cicuit Cut the trace direct after the HV diode   see  below the point "test onderbroken" 860k  gave a drop of only 100V    no problem for the HV regulator the resistor can be low Wattage only 0.0116 W 100V 860k The cathode current is 116uA neglecting the low parallel load of multiple M OHm Since then only 1 time there was a breakdown of all voltages "light outage" but just switching off and on and all was working again  no collateral damage... I use the Tektronix 465 again and live with the occasional break downs until i find a KRT replacement. But  after some warm up time with break downs and return it works stable for hours. BTW a 100MHz b.t.w. Hantek DSO5102P USB Digital Storage Oscilloscope 2Channels 100MH...

LOTW Sorted by QSO Date (0.018764 seconds elapsed) Next   Call sign Worked Date/Time Band Mode Freq QSL Details PA0O K5CD 2017-12-29 01:08:15 80M FT8 3.57355   Details PA0O UN7DAT 2017-12-29 01:01:00 60M FT8 5.35762   Details PA0O MM0HVU 2017-12-28 08:07:45 80M FT8 3.57346 SCOTLAND Details PA0O PZ5RA 2017-12-28 07:33:30 160M FT8 1.84056   Details PA0O 3D2TS 2017-12-28 07:13:00 30M FT8 10.13769 FIJI ISLANDS Details PA0O K9SE 2017-12-28 06:36:15 160M FT8 1.84060 UNITED STATES OF AMERICA Details PA0O XE1TD 2017-12-28 06:19:00 160M FT8 1.84060 MEXICO Details PA0O WA3HQK 2017-12-28 06:00:45 160M FT8 1.84058   Details PA0O K9SE 2017-12-28 05:49:45 160M FT8 1.84058 UNITED STATES OF AMERICA Details PA0O HK3W 2017-12-28 05:17:30 80M FT8 3.57544 COLOMBIA Details PA0O K5SUL 2017-12-28 00:34:00 60M FT8 5.35833   Details PA0O WA8QYJ 2017-12-28 00:31:00 60M FT8 5.35833 UNITED STATES OF AMERICA Details PA0O K8SIX 2017-12-27 23:39:45 60M FT8 5.35...

PA5X  Johannes C93PA Mozambique  op 60m in FT8 mode  met grote pile up strong  0  to -4 https://dx-world.net/c93pa-mozambique/

  21/28 MHz back to 1 element dipole. Only receiving wind lately

The Beverages bring me in the WSPT Challenge top 10  for 160 and 80 But not even in 600m  list no matter how often and "strong" WA4SZE and AA1A  are received. Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az  2017-12-24 04:28   W4BCX   0.475686   -28   0   EL98pd   5   PA0O   JO33hg   7368   41   2017-12-24 02:50   WA4SZE   0.475653   -31   0   EM65   0.2   PA0O   JO33hg   7147   41   2017-12-24 03:58   AA1A   0.475687   -22   0   FN42pb   5   PA0O   JO33hg   5630   49 Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az  2017-12-24 00:20   W9MJW   1.838122   -17   0 ...

MAX9814  seems the best choice  it has AGC and jumpers for gain setting to max 60dB  will test this one to when arrived.  Received this low noise ST TS472  pre-amp  Diymore from eBay. Main while the 3 transistor pre-amp with AVR earlier down in the blog works fine. This TS472 IC is special designed for microphones  electret or magnetic and i was curious to find out how such integrated device performs. With the magnetic  200 OHm Peiker element the signal is fine although not as sensitive as with an electret element. The maximum un-clipped output is about 2Vtt. It did not match the low impedance mike input of the Condor as it is at first test. Minimum drive load is 10k.  An emitter or source driver is needed behind the TS472 and  low impedance tranceivers like the Condor.  No documentation is supplied with it but the PCB looks similar to the  ST  demo board TS472 PCB  well designed.   ...