Skip to main content

How to quiet the IC706?

The IC706 ( ohne alles)    is a great set  but has an annoying fan  that always runs. Now using it again for receiving  137kHz  it becomes a problem if you switch of the IC706 it is a relieve.
I tried to find if something could be done about that noise.
The FAN runs at lower speed during receive.
There is an 47R  in series that is shorted during TX (the schematic says 470Ω  but i doubt that.This R is located at the PA board close to the connector of the FAN. It is a power SMD.
Recently i got an SMD soldering station the AOYUE 968   this great demo is the 962 without the extra 30W soldering tool  http://www.youtube.com/watch?v=MOEHstgaVLM real nice  3 functions in one  120€  Elektroshop  real heavy device 5kG?  8€ shipping costs.  incredible how they can do it! 
But not to hasty .. first test and measure before changing anything.
Had some exercise with a defective Satellite  converter  real interesting parts that normally would just be wasted.
What about a I2C controlled 2.6GHz synthesiser with just a few parts? and UHF transistors and FETS ...
It failed to run the IC706 with the fan off,  it heats up to much. This IC706 was  designed in the times that power saving was not a big issue. Compared to the K3 this one is like a small vacuum cleaner...
So  i did not got a solution.   Testing a higher R  could be lowering this noise.  Bringing down the idle power consumption has to be done first and second lowering the fan.

To PE4BAS,  Bas 137kHz needs a small filter for the 0.1388  strong digi signal DCF37 and others nearby. So i had to use the 500Hz CW filter  WSPR receives only in CW-reverse  but the WSPR setting need adjustment.  Can this CW-N filter be used in USB mode as well?  is there a mod for that?

Comments

PE4BAS, Bas said…
Hello Jaap, there is a mod for the fan as well as use of the CW-N filter in SSB mode. Wrote about it in my blog long time ago. See http://pe4bas.blogspot.com/2009/04/laatste-upgrade-van-mijn-icom-706.html. You can find the fan mod here. This will increase cooling on receive but not while transmitting. I did this mod and noticed the Icom does not warm up as much as it did before. Although the noisy fan does come up when transmitting, but not as fast as it did before except in summertime of course. Good luck !
73, Bas

Archive

Show more

Popular posts from this blog

2011-01-22 DIAMOND 2m 70cm 1m30 Colinear inside

Having relative poor signals on the local 70cm / 2m channels using this X50 Diamond collinear 70/2  1m antenna at a height of 25m. I needed to investigate what could be wrong. Measuring the cable only 3W is left for the antenna of the 10W 435MHz output from a IC451E The cable is 30m type H100 Z50 10mm outside diameter it is semi air-spaced but has an impossible 4mm² solid CU inner conductor not much air left. I preferred the H43 Z75 cable having lower loss and mechanical better ratio in conductor size. My antenna uses SO239 connector UHF type semi air spaced isolator.  3W should be enough for a comfortable noise free FM signal. But only 27km away at PA0A the signal is weak too weak something must be wrong? I made a simple reference dipole of 2x17cm CU wire. With this dipole the signals where totally worse. So the Diamond does work? I got curious to look inside. Maybe moisture penetration degraded the antenna. This  antenna is rainwater close in its normal vertical mounting posit

SPF5189z Low noise preamp 23cm

 14-4-2018 updated Above the low noise  preamp 50 - 4GHz    ebay  6€ Tested  2 small porto antennas 1 Baofeng UV antenna left   2nd best signal on PI2NOS 2 eBay DIAMONDSRH805S  wide band 144/432/1200  it works for its size as expected 3 piece of wire :   best signal in the setup... Unit under test at workbench. It was stable  50mA  at 5V   few days,  but sudden the current went up to 100mA And i could  no longer adjust it with the negative bias Voltage. The - Voltage went to zero and the SPF input port became low Z. This SPF5189z was broken  no oscillations, no input overload just it broke while i was receiving the PI2NOS 430.125 using a small antenna at the workbench. The specs of  SPF5189z  say it has an internal circuit  regulating the bias current. Replaced . again   with an other of the 5 spare SPF i have. The new one again could be adjusted at 50mA  5V  The current raises to 150mA  when removing the  negative gate voltage. Where is that internal bias cir

BIJZEN mast en ontwerp fouten.

In 2013 heb ik een Bijzen aluminium mast 3 x7m  opgehaald  bij iemand die hem niet mocht plaatsen Gemeente Oss  dat zegt misschien al genoeg.. Pas in 2018 heb ik hem geplaatst had ik veel eerder moeten doen. Mooie mast, mijn xyl vond hem zelfs mooi. Hij is licht, de 3 delen wegen  235kg  het vaste deel 102kg dus het te lieren gedeelte weegt   slechts 133kg + ca 50kg rotor + antennes etc.  De elektrische lier is wel erg zwaar 30kg misschien wel maar die zit onder    Antenne  3ele Steppir  19kG  +  G2500DXC rotor: 3.6kg  + rotorbuis 12 kg  +  kabels 10kg  + 5/7 ele 6m beam. ongeveer 50kg Je moet niet te dichtbij  kijken, dan valt op dat het Aluminium lastwerk heel slordig is gedaan, scherpe bramen aan de lassen waar kabels door kunnen worden beschadigd of haken Er is zeer ! weinig ruimte voor de rotor een YAESU G2500DX past net maar dan ook net  met beetje buigen van  kruisverband. Het Rotor platform kan wel een meter hoger dat geeft meer  buislengte boven het zit nu op 3.5 meter van het