Electronics Forum > Test Equipment

heathkit sb 614

<< < (3/3)

kinkydoints:
Im learning everyday , helps as far as some of the categories that are covered in the test for my ham ticket. I am also replacing all electrolytic caps to new ones , some of the original ones I can not match up exactly , I have read that if the mf rating is not exact than the next closer higher is the rule of thumb. most of the voltages are also close , like 10 mf at 9v turned into new 30 mf at 15 volts.   50mf is a 100mf and the  250mf went to 300mf. how about those (4 )green 10K ohm 7watt round resistors can I upgrade those with new? what would you recommend for replacements ?    (1) 2K ohm 10 watt square wire wound? t I think they are in the pic on this post. I like working on my stuff  " indoors" not like my full time job...

k7rmj:
For the resistors you should keep the resistance value the same. Keep the same number of ohms. It actually depends on which part of the circuit the resistor is in. But, if it functions as a dropping resistor and you change the value of it the voltage drop will also change and could throw the required voltage or the current way off. That could be a disaster in some circuits. The power rating of the resistor is not as critical as long as your replacement is rated for MORE power than the original.

I'm not real sure on the value of the caps. But, I would thing that you want to keep their values close to the original values. Again, it depends on the circuit the cap is used in. If you had to replace a 10 uF cap I would not go over 20 uF and I would feel real uneasy about that too. a 12 uF would be a better choice. But, again, that is just my opinion and I might be full or old wives tales LOL. It wouldn't be the first time either.

Just my 2 cents. Good luck with it.

73 DE K7RMJ  Frank

kinkydoints:
K7rmj thanks for the advise , I did replace the two high 50mf caps with the 10mf . they were both 16 volt , so no changes to the circuit they where in.. I still would like to get those old green resistors ( 4 ) as well as that square wire wound changed, maybe with a newer type? they seem really long, as far as resistors go, new ones might not be that long even with the leads extended to the though holes? no worries I like working on this unit. I wonder if the work I have done can be tested in a shop that knows the in's and out's of these Heathkit  monitors.

kinkydoints:
well Im hooked...after the sb614 station monitor I purchased and recapped I am looking to get some equipment to check and learn how to do a basic Alignment   ...the next addition is a PC USB 2CH 60M 200MS/s Digital Oscilloscope 60M Spectrum analyzer Data Recorder , as well as a DANIU FY3224S (FY3200S-24M) 24MHz Dual-channel Arbitrary Waveform DDS Function Signal Generator Sine Square Wave Sweep Counter, VICTOR VC3165 110V-220V Professional Precision Frequency Counter Meter. also got a cheap cobra 19 plus . to do these tests on. I need to get some kind of an attenuator ? are these a good start? cheap ya...
point me toward some reading material that covers old school  Alignments and tools? Did I go too fast here in my equipment? as far as the 11 meter band will that FY3224S work in this application.  thanks

Navigation

[0] Message Index

[*] Previous page