Introduction Amateur radio VHF PA - July 2021

VHF PA - July 2021

by
Viliam OM0AAO / OM0A
-
Mapa spojení vo VKV prevádzkovom aktíve - júl 2021
Connection map in VHF operating asset - July 2021

Summer months broadcast in nature. That's why I headed over the village of Horná Súča again, part Vlčí vrch. Compared to last month, several new products have been prepared.

Amplifier with LDMOS MRF9180 and transceiver R2CW

The first is an amplifier with LDMOS MRF9180. I chose this type, because I have a 28V power supply. I managed to assemble the amplifier and prepare it for cooperation with the R2CW transceiver. It's a better transceiver to race than Kenwood TR-751E. However, there is also a difference in the connection of the amplifier control, where R2CW gives a positive output voltage when transmitting while most transceivers give 0V or a circuit.

To increase comfort, I created a hanging table for the car. However, the seat is more comfortable to sit than in the trunk of a car.

Hanging table with R2CW transceiver and MRF9180 output stage
Hanging table with R2CW transceiver and MRF9180 output stage

The weather was good, the weather forecast promised only a little wind. It takes about half an hour to set up the antenna and prepare the workplace. As a last thing, I wanted to start the generator. After all, the sound of a running engine may not be a pleasant thing. But the generator did not start. At first, second, third or fourth time. Because to solve problems of this type on the hill is impossible, so I quickly disconnected the whole workplace and replaced the setup with Kenwood TR-751E and battery power.

Directional map of the connection in the VHF operating asset - July 2021
Directional map of the connection in the VHF operating asset – July 2021

I'm starting the VHF operating assets there with a smaller delay, which is irrelevant, but more disappointment from the forced setup change. After all, it represents 100W compared to 25W 6 In addition, the dB plus of the advantage of the signal compressor and the quality of the R2CW transceiver will also manifest itself.

Car hanging table
Car hanging table

A big positive, however, was the hanging table. Rotating the antenna was still manual, but whether the transceiver or laptop is much more comfortable to operate. The hanging table is attached with two carabiners to the headrests of the seats. The size is 120 x 30 cm. Stability is better than I expected. At higher loads, it is advisable to shorten the tensioning cables in this way, to correct the table being pushed into the seat.

What performances are used in VHF PA?

I used ON4KST more intensively because only a few stations came to the call and calling is also more difficult when searching.. The performance average seems to be somewhere else.

For illustration, according to the reports from this round of VHF Operating Assets in OK 58 stations declared the power used. The diameter is based on 238W, which is almost 10 dB more than on my side.

Comparative map of OPK stations from VHF PA 07/2021
Comparative map of OPK stations from VHF PA 07/2021

You can view the connection map to OK composed of two images. Tam, where the lines end with a small circle, there was a station there. Tam, where is the red pin, I made a connection there. Maps do not completely overlap, but that's probably enough for illustration.

And a practical example: for example, if the station uses 4×9 elementov a 500W, so its audibility for me may be sufficient even if the antenna is pointing elsewhere, but 25W on my part is not enough to make the connection.

Locator map
Locator map

This time I also heard a German station and the station from Bosnia and Herzegovina was a surprise, E71EBS. He was also pleased with the growth of Polish stations. If there were even more, it would be even better.

Missing VHF PA multipliers

It's at the end 61 QSOs and 17 locators, which is less than a month ago. For example, the JO80 locator is missing, JN77, JN87 or JN97. But it is a pleasure JN94.

Locator map
Locator map
Connections by country
Connections by country

http://www.opencontest.org/edi/map/20210719141307000098OTBCMU

What next time? It is definitely necessary to ensure a reliable power supply, to work with power of 100W and R2CW. New antennas are also being prepared. GL!

Diary OM0AAO from VHF PA

date time Call Mode Sent Rec WWL claimed
QRB		 calculated
QRB		 2way CC
210718 0803 OK4DJ 1 59 001 59 003 JN89FN 127 127
210718 0804 OM6ABF 1 59 002 59 009 JN99CH 42 42 ✓
210718 0807 SP9RQH 1 59 003 59 007 JO90TC 174 174
210718 0809 OE6V 1 59 004 59 047 JN76XU 280 280 ✓
210718 0813 9A1DL 1 59 005 59 047 JN85WF 418 418 ✓
210718 0815 S59A 1 59 006 59 031 JN76XQ 296 296
210718 0817 OM6TX 1 59 007 59 015 JN99JK 80 80 ✓
210718 0819 OK2OZL 1 59 008 59 013 JN89UE 30 30 ✓
210718 0822 OK1KQH 1 59 009 59 028 JN79GO 258 258
210718 0825 OK1DOL 1 59 010 59 034 JN69OU 358 358 ✓
210718 0826 OM5UM 1 59 011 59 009 JN98EO 52 52
210718 0828 OM3CQF 1 59 012 59 030 JN88RT 41 41
210718 0830 9A2AE 1 59 013 59 086 JN86HF 322 322 ✓
210718 0831 OK2DTF/P 1 59 014 59 035 JN88VW 14 14
210718 0832 OK2VLT 1 59 015 59 035 JN99CS 90 90
210718 0837 OK2BUB 1 59 016 59 025 JN99EQ 85 85
210718 0841 OK1GI 1 59 017 59 017 JN89EX 160 160
210718 0843 OK2BMJ 1 59 018 59 017 JN89VC 19 19
210718 0846 9A3SM 1 59 019 59 061 JN85FW 357 357 ✓
210718 0847 OM5LD 1 59 020 59 030 JN98AH 75 75
210718 0849 OK2CVH 1 59 021 59 025 JN89VJ 48 48
210718 0850 OK2RSC 1 59 022 59 012 JN89QH 57 57
210718 0854 OK2MAJ 1 59 023 59 023 JN89SG 45 45
210718 0855 OK2BSP 1 59 024 59 032 JN99AK 52 52
210718 0856 OK2VZE 1 59 025 59 044 JN89JM 104 104
210718 0858 OL70KRT 1 59 026 59 047 JN99BK 53 53
210718 0900 HG1DRD 1 59 027 59 084 JN86KU 250 250
210718 0902 9A2DM 1 59 028 59 041 JN86KD 306 326 ✓
210718 0904 OM3CVV 1 59 029 59 016 JN88TR 21 37
210718 0905 OM4KK 1 59 030 59 016 JN88WS 5 24
210718 0910 OM1MJ 1 59 031 59 022 JN88PE 82 101
210718 0912 OM2ABC 1 59 032 59 002 JN88QA 96 115 U
210718 0913 OM3CPW 1 59 033 59 026 JN88OD 89 108
210718 0915 OM5ZX 1 59 034 59 019 JN98AP 23 38
210718 0919 OM3TFP 1 59 035 59 003 JN98EV 38 32
210718 0921 OM4AJH 1 59 036 59 007 JN88XR 12 28
210718 0925 S56P 1 59 037 59 103 JN76PO 313 331 ✓
210718 0926 OM4AY 1 59 038 59 012 JN99FF 63 46
210718 0931 9A7D 1 59 039 59 075 JN95CI 386 404 ✓
210718 0933 OK2TSG 1 59 040 59 072 JN99CR 105 86
210718 0936 OK2RAS 1 59 041 59 039 JN99FP 102 83
210718 0941 SN9W 1 59 042 59 073 JO90PP 228 209 ✓
210718 0947 OK1KMP 1 59 043 59 108 JO70UK 239 230
210718 0950 YU7ACO 1 59 044 59 074 KN05RD 490 502 ✓
210718 0953 OK2BSQ 1 59 045 59 024 JN89VS 107 89
210718 0954 OK2KPS 1 59 046 59 053 JN89WH 56 38
210718 0957 S57O 1 59 047 59 143 JN86DT 252 272 ✓
210718 0959 OK1DTP 1 59 048 59 103 JO60VR 363 357
210718 1000 OK1KKL 1 59 049 59 064 JO70PO 273 264
210718 1001 OK1KTW 1 59 050 59 068 JN89IW 151 140
210718 1017 9A0V 1 59 051 59 146 JN95PE 418 434 ✓
210718 1021 9A7DI 1 59 052 59 054 JN85VQ 348 367 ✓
210718 1026 E71EBS 1 59 053 59 095 JN94GR 457 475 ✓
210718 1027 OK2KOL 1 59 054 59 042 JN99CN 87 68
210718 1030 9A0BB 1 59 055 59 204 JN85EI 401 421 ✓
210718 1041 9A8D 1 59 056 59 179 JN95LM 376 392 ✓
210718 1042 9A2B 1 59 057 59 063 JN75SL 411 430 ✓
210718 1052 OM0RW 1 59 058 59 044 JN99RC 121 111
210718 1055 OK2KJI 1 59 059 59 099 JN79TI 175 175
210718 1056 OE3TFA 1 59 060 59 029 JN78UQ 160 168
210718 1059 OM2RL 1 59 061 59 072 JN88NR 56 68

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