...if your desired language isn't available, the alternative language will be shown...
informatie pagina voor experimenteel radio-onderzoekers

  Item for sale
  Item adressen
  Item fail-gallery
  Item press information
  Item weblog/news

 apparatuur foto's
  Item HP 331A distortion analyser
  Item Philips PM2524 multimeter
  Item Rigol DS-1054Z
  Item Sayrosa 261 frequentieteller

 applicaties (pc)
  Item UI-View (APRS)

  Item 27Mc
  Item FRS
  Item LPD
  Item PMR

  Item (E)EPROM
  Item crystals
  Item resistor coding

  Item RF Technology Days 2016

  Item 12VDC connector
  Item coax connectors
  Item Condor 16
  Item TNC connector

 Racal Cougar
  Item 0. Racal Cougar
  Item 1. introduction
  Item 2. compnents
  Item 3. assemblies
  Item 4. technical
  Item 5. modifications
  Item 6. data protocol
  Item 7. service

  Item boeken
  Item handleiding FUP1DZ
  Item jargon
  Item Morse code
  Item NATO alphabet
  Item Q-codes
  Item radio notebook

  Item 6H2N-EB / ECC83 / 12AX7
  Item algemene informatie
  Item ATP4 elektronenbuis
  Item elektronenbuis codering
  Item elektronenbuizen
  Item gloeistroom/-spanning
  Item reactiveren/reformeren
  Item stabilisatiebuizen

  Item 23 cm duplex filter
  Item Aerial Facilities BPD-410/420-3N
  Item Celwave P522 UHF duplexer
  Item Hoxin DX-720 diplexer
  Item JWX triplexer bc/2m/70cm
  Item Kenwood LF-30A LPF
  Item Motorola UHF cavity combiner
  Item Radiosystem RS460 cavity BPF
  Item stub filter [EN]
  Item basics: diplexer or duplexer

  Item AM-65/GRC
  Item LV-80 RF PA
  Item RT-70/GRC
  Item SEM antennetuner (AGAT)
  Item SEM25
  Item SEM25 gloeispanning
  Item SEM35

  Item krimplak
  Item schroefdraad
  Item verspanen

  Item 10/20/30 dB att
  Item BG7TBL noise source
  Item Daiwa CN-101L
  Item Daiwa CN-801
  Item HP P382A attenuator
  Item x-tal tester (DIY project)
  Item Krohn-Hite 4100 signal generator
  Item Radiosystem AB dummy load
  Item Rigol DSA815-TG
  Item Rohde&Schwarz SMT 02
  Item Spinner BN 52-77-66
  Item Zetagi DL50 dummyload

  Item 10 MHz low pass filter
  Item Frequency Electronics FE-5680A
  Item HP 10811 OCVCXO
  Item RS920 10MHz oscillator
  Item RS920 OCXO timestandard
  Item timestandard (general)
  Item time standard; BG7TBL
  Item tijdstandaard; VE2ZAZ
  Item time standard; W5OJM
  Item Trimble 34310-T OCVCXO
  Item Yaesu FT-8x7 (TC)XO

 meetapparatuur (info)
  Item (poor mans) spectrum analyser
  Item dummyload
  Item frequentieteller
  Item functiegenerator
  Item meetverzwakker
  Item octopus component tester
  Item oscillator adjustment
  Item staandegolfmeter
  Item test- en meetapparatuur

  Item Counter 1 MHz input mod.
  Item Yaesu FT-897/FT-897D
  Item Yaesu MH-48 lock mod

  Item (coax) kabels coderen
  Item APRS
  Item AWG draadtabel
  Item coax kabels testen
  Item Yaesu FT-8x7 CAT port
  Item paneelbouw

  Item (remote) coax switch
  Item afregelen FT-8x7(D)
  Item APRS basispost
  Item APRS tracker
  Item coax switch 1-8
  Item condensator microfoon
  Item counter prescaler
  Item CTCSS module
  Item FT-2000 headset
  Item FT-2000 remote
  Item FUP1DZS meetzender
  Item Geloso G.1/1040-A
  Item Geroh AKAC019 liermast
  Item go-kit
  Item headset (Avcomm)
  Item hoofdtelefoon versterker PL500
  Item Icom IC-25E
  Item Kerona AR-301 rotor
  Item KLV 400 RF PA ombouw
  Item Lineair 400W (Frinear)
  Item MFJ-948 antennetuner
  Item parallelle poort controller
  Item Pixie CW TX
  Item programmeren FT-8x7
  Item Samlex SEC 1223 voeding
  Item TH-D7E tracker
  Item Tinytrak 4
  Item uTracer 3+
  Item voedingsconnector FT-897
  Item VSWR SA meetbrug
  Item Yaesu FT-857/897 meter
  Item zwaai Alinco DR-135E MkII

  Item elektromigratie in filters

  Item Ameritron ATR-20 tuner
  Item Baofeng UV-5R
  Item Diamond X-30N rondstraler
  Item Icom IC-2e
  Item Icom IC-7300
  Item Kenwood TH-D7E
  Item Kenwood TS-830M
  Item MFJ-901b antennetuner
  Item MFJ-948 antennetuner
  Item MFJ-971 antenna tuner
  Item QYT KT-8900
  Item Triple-P TXU-1256 repeater
  Item Wouxun KG-UVD1P
  Item Wouxun speakermike
  Item Yaesu FT-101E
  Item Yaesu FT-1500M
  Item Yaesu FT-2000
  Item Yaesu FT-7800
  Item Yaesu FT-817
  Item Yaesu FT-857(D)
  Item Yaesu FT-897(D)
  Item Yaesu FT-8x7 serie
  Item Yaesu FT-991

  Item capacitors
  Item Geloso 3227 versterker
  Item Kenwood TS-830M
  Item Lorenz SEM25
  Item Yaesu FT-897D

 Rigol DSA815-TG
  Item meting: omroepband
  Item test: overspraak TG
  Item test: TG signaal

  Item elektret microphone
  Item Time Domain Reflectometer

 surplus apparatuur
  Item Bosch Condor 16
  Item Motorola GM950 (70 MHz)
  Item Rohill R-2050

 telefonie surplus
  Item Ericsson F-955
  Item Ericsson F-955 modifcations 2017
  Item Ericsson RS203/RS2062
  Item Nokia NCM30
  Item Nokia NNF30
  Item Nokia RD72
  Item Radiosystem monitoring unit
  Item Radiosystem RS922
  Item Radiosystem RS923
  Item Radiosystem RS950
  Item Radiosystem RS951
  Item Radiosystems RS963
  Item Radiosystems RS9694
  Item RS925 service box

  Item aarding
  Item antenna rotor
  Item antennetuner
  Item circulator/isolator
  Item snubber diode

  Item Minipro TL866 programmer
  Item Velleman VTSSC50N soldering iron
  Item Yihua 852D+ soldeering station
  Item ZD-409 desoldering tweezer
  Item ZD-915 desoldering station

  Item soldering
  Item workshop tips

  Item decoupling capacitors

  Item Beryllium oxide
  Item EM veldsterkte
  Item radioactiviteit
  Item harardous radioation?

  Item SV500

Radiosystem AB dummy load

A long time ago I bought a Radio System AB (Ericsson) 50 Ohms dummy load with N-connector for testing purposes. It’s a dummy load from the former NMT450 mobile phone network. It’s likely these dummy load were fitted to the front of the RS460 cavity band pass filter. The footprint, paint color and structure and four holes of the dummy load match perfectly to the unpainted square on the front of the RS460 filter boxes. Possibly the dummy load were used to dissipate sideband energy…
The nice thing about these dummy loads it equipped with a BNC test point. The internal chip resistor has a test point which is connected to the BNC socket. This is for example convenient for frequency measurements. The RF power is dissipated into the chip resistor and a relative low power test signal can be used to feed a frequency counter. I guess the chip resistor can handle at least 100 Watts of RF power when fitted to a heatsink.

image is loading...

The dummy load is used for seven years now. And since I bought a Rigol DSA815-TG spectrum analyzer recently, this is a nice opportunity to determine the power reduction at the test point. I normalized the test setup and measured the loss. I would expect the signal reduction is linear, but I was wrong. The signal reduction of the test point is logarithmic. The lower the frequency, the more the signal reduction at the test point and vice versa. Luckily I updated the firmware of the Rigol DSA815-TG spectrum analyzer and has now the option to show the frequency scale logarithmic instead of linear. Therefore the bent signal reduction line on the screen appears quite linear! Using the CSV export function I exported the trace information to Microsoft Excel. After fiddling with the graph function I added a “trend” line that fits very nice onto the trace of the measurement. There’s a convenient option to show the formula of the trend line. Since the trend line fits very well it’s safe to say that the formula fits therefore also the signal reduction. The determined formula is this: [dB] = (7,527 × f [MHz])-72,44. If a frequency in MHz is multiplied with 7,527 and the result is reduced with 72,44, the answer is the signal reduction in dB relative to the input.

image is loading...

image is loading...

For convenience I calculated the signal reduction for the regular ham bands. The results are shown below. The dummy load is used for approximately 460 MHz and should work fine up to 3 GHz. I cannot verify this since my equipment can measure “only” op to 1,5 GHz. Assuming the formula fits until 10 GHz, the numbers should fit. But it’s possible the dummy load will behave different at “extreme” frequencies (above 3 GHz). So beware not to blow up the input of your measurement devices. Normally a spectrum analyzer is very sensitive for overload at the input. Be sure to calculate/verify the test point signal strength at certain frequencies and input power. For example the Rigol DSA815-TG can handle +20dBm at max. If a HF transmitter (1,8…28 MHz) is tested, the least signal reduction at the test point is -47,4 dB. The maximum signal at the input port if the dummy load is +67,4 dBm. The maximum input power is therefore 5.495 Watts. Since the dummy load can handle approximately 100 Watts, it’s safe to say that your DSA815 won’t be damaged testing an 100 Watts HF transmitter. At 435 MHz the signal reduction is 26,7 dB. The maximum input is +20 dBm, therefore the maximum power input is +20 dBm + 26,7 dB = +46,7 dBm = 46,8 W! There are several 70 cm transceivers and amplifiers delivering more than 50 Watts, so beware that this could (or will?!) damage the DSA815 applying more than 46,8 Watts to the dummy load input.

1,8 MHz = -68,0 dB
3,5 MHz = -63,0 dB
5,3 MHz = -59,9 dB
7 MHz = -57,8 dB
10 MHz = -55,1 dB
14 MHz = -53,6 dB
18 MHz = -50,7 dB
21 MHz = -49,5 dB
25 MHz = -48,2 dB
28 MHz = -47,4 dB
50 MHz = -43,0 dB
145 MHz = -35,0 dB
435 MHz = -26,7 dB
1,3 GHz = -18,47
2,3 GHz = -14,2 dB*
3,4 GHz = -11,2 dB *
5,8 GHz = -7,2 dB *
10,0 GHz = -3,1 dB *

* These numbers are based on the formula and not verified in a real world measurement.

open de afdrukbare pagina door hier te klikken

contact the administrator
If there are questions, notifications or other kind of information, please let me know by sending a messege to me by using the contact form below. If a responce on your message is desired, please make a note of it in the message. is. In this case, be sure your e-mail address is filled in on the form below.
Note; This message will be sent to the administrator and will not be shown om the website.
name (and callsign):
e-mail address:
Type 1586 in the form field as a check: - © 1984...2017 - Build: 20161003