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No.    174   
Kit / Parts     Kit   
Class.     Measurement   
Part Name     K7105   
Shop    Shop :  Quality Kits (http://www.qkits.com/serv/default.asp)
Manufacturer : Velleman (http://www.velleman.be)
Price     Quality Kits price :

$250.00 CDN(Canadian dollar)  on Dec.15, 2002

$299.99 CDN (Canadian dollar)  on Feb.10, 2001 (When I bought it.)

Main parts     LF357 741 311 74HC4052 4052 TDA8703 VK7105(PIC16C65)   
The power supply     9VDC
>200mADC (Option : NiCd Battery)

Table 1 Specification

Input channel 1ch   
Input Impedance 1Mohm 20pF
Input sensitivity 5mV/div to 20V/div (refer to Table 2)
Vertical resolution 8bit ( 6bit on screen )
The maximum input voltage 100V (AC+DC)
Input coupling    DC, AC, GND
Input bandwidth 750kHz (-3dB at 0.4V/div setup)
Sample rate Single Shot events : 0.5MHz
Repetitive signal : 5MHz
Time range 2us/div to 20s/div (refer to Table 3)
LCD display LCD 64 x 128 / Waveform display area 64 x 96
Sine wave generator 400Hz (CR oscillation) 1Vpp/10kohm (adjustable)
PC interface    RS-232C (TX signal output only)

Baud Rate=9600 , Data=8 bit , Stop bit=1 bit , Parity = No , handshaking = off

Digital Signal Output Required 3mm Stereo jack

Center : TX signal of RS-232C
Outside : Sine wave output

Table 2 Voltage setup
Table 3 Time setup
Time Base Time Base    Time Base   
2us    4us    10us   
20us    5us    0.1ms   
0.2ms    0.5ms    1ms   
2ms    5ms    10ms   
20ms    50ms    0.1s   
0.2s    0.5s    1s   
2s    5s    10s   


Print Circuit Board    VELLEMAN P7105'4   
Case     Including a plastic case with an internal shield sheet
Size     130 x 230 x 43 mm ( 5.1"x 9"x 1.7" ) 600g   
Additional parts     Probe , AC Adaptor , 3mm Stereo jack , etc.
  • Carry case: BAG 13 x 24
  • Probe: PROBE100
  • PROBE60S: safety probe with isolated BNC connector
  • Mains adapter: PS905
  • Rechargeable batteries: HR6/9 ( 6 pcs. )
  • Rubber Protection Holster: PCASE


Modify     Software for PC's RS-232C  : http://www.velleman.be/download.htm#hhs5   
Example     [ Outline ]

kit174a1.jpg (27195)

Size 355 x 225 x 73 mm

[ Package ]

kit174b1.jpg (34891)

[ Inside of a package ]

kit174c1.jpg (36618)    kit174d1.jpg (28183)   

[ CRs pack ]

[ Mechanical parts ]
kit174e1.jpg (19305)    kit174f2.jpg (15327)   

[ LCD and ICs ]

[ Cases ]


kit174g1.jpg (51358)

[ A Main printed board ]


kit174h1.jpg (15737)

[ Operation key ] 

kit174i1.jpg (26743)

[ Parts list / Assembly procedure document ]

kit174j1.jpg (25248)

[ Manual / Guideline ]


 kit174k1.jpg (56254)

[ Parts of CRs ]


kit174l1.jpg (25863)

[ Parts of LCD and ICs ]


kit174m1.jpg (28009)

[ Mechanical parts ]


kit174n1.jpg (22345)

[ Parts of cases ]

[ Manufacturing ]

This kit (main printed board) is assembled in the order of a parts list.

  •  The taped parts, which is shown in the picture "Parts of CRs" (jumpers, resistances, diodes, inductors), are arranged in the order of this parts list.
  •  The main printed board is a double side printed circuit board. But, this board doesn't have the through hole. For this reason, we must short between a part side and a solder side with jumpers or parts lead wires. The jumpers with "(S)" on this parts list are required the soldering on both a parts side and a solder side.
  •  TP1 which is a square wave for a calibration is a copper plate. This manual shows that this plate is mounted on a solder side. I am afraid of the short between this plate and a shield sheet. So, I mounted this plate on the parts side.
  •  The reset switch SW3 is mounted on a solder side. We have to adjust the position against the hole of bottom case.
  •  We have to check the jumper's connection carefully. It is easy to find the un-working jumpers if we check the non-solder pads.

[ Main board ]

  •  The parts list shows the spacers, which joins between main board and LCD module board, have 15mm length spacers and 8mm length spacers. But this kit has 20mm length spacers. So, I must modify the 25mm length joint connector for the signals between the main board and LCD module.

[ Main board with LCD Module ]


[ Adjustment ]
  •  I adjusted this board above the step. This adjustment was easy against my expectation.
  •  This adjustment is shown the 3 pages in this manual.
  •  I covered the spacer near the TP2 by the vinyl tape for short prevention.
  •  This adjustment requires a digital multi tester which can measure the RMS value of AC voltage.
  •  The procedure "1 -Adjusting the input amplifier offset voltage" shows that TP5 and GND are shorted. This means that U2(741) output is connected to GND. I removed U2 from U2 IC socket while this adjustment.

  •  The shield sheet is mounted inside a bottom case. The surface of a main board side on the shield sheet is coated by insulated sheet. I stuck this shield sheet on the bottom case with the double-sided tape.

[ Bottom case with the shield sheet ]


[ Bottom case with the main board and the shield sheet ]


[ Inside view with battery boxes ]


[ Back view with the support parts ]


[ Normal operation view that a sine wave is measured. ]


[ Aquision of a PC ]

 A PC can communicate to this kit by using a downloaded hhs5.zip (201kB) from http://www.velleman.be/download.htm#hhs5. This hhs5.zip contains HHS5.EXE. This HHS5.EXE is the software of an aquision and a waveform display.

 HANDHELD SCOPE / K7105 is transmitted the measured data to a PC only at once when HANDLE SCOPE / K7105 is turned on. This procedure of an aquition is indicated below.

  •  The HHS5 software is started.
  •  A signal is measured by the HANDLE SCOPE / K7105.
  •  The power switch on the sheet key of HANDHELD SCOPE / K7105 is pushed, and it once turns off.
  •  This power switch is pushed, and it turns on again. At this time, the data is transmitted from HANDLE SCOPE / K7105, and HHS5 software displays waveform data.

"Smooth" /  "Bar" / "Dot"

[ Sample of HHS5.EXE ]

HHS5 receives the data which the range of all value are from 0 to 255. I conform the 8 bit resolution.

[ My impressions ]

 Size is small.  It is an advantage for me.

 Don't expect an accuracy.

 I don't wish to try the making this kit again, because this kit has many parts.    

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HANDHELD SCOPE / K7105 (Japanese Edition)

Special attention

© 1997-2017 Atsushi Itou , JH4CBA , CBA

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