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Other Video Blogs / Re: GE Table Top Restore from the 70's
« Last post by nor4277 on July 18, 2019, 10:28:48 PM »
I have a it's the Mickey mouse version ,but the chaos looks the same as your ,except in the kids version for safety is a transformer so,mine won't be a hot chais,I sent for and got replacement caps for mine ,except mine plays perfect ,I trying to figure if I should just go ahead and replace the caps or wait what do you think.
Test Equipment / Care and Safety for Spectrum Analyzers
« Last post by guitar_199 on July 15, 2019, 10:16:51 PM »
Somewhat depressed.  :)

I picked up an older Hameg Spectrum Analyzer at a hamfest back in May.    I know very very little about them but I am learning fast.  Catching up on dBs, dBms, attenuation.....but the big thing I am concerned about is the safe handling of what I stuff in to it.   I know that you have to attenuate the transceiver down to a safe level but it seems that there are a number of ways to do this... and all of them appear to be in the thousands of dollars.  Not only that, I have not found any place that discusses just HOW you set them up.

Some say "use attenuators".   A nice 100W 40db would knock most low powered transceivers down (thinking 5 - 10 watt, I still love CBs!!!!!)  BUT here is the question.... if you go from the radio to the attenuator and the attenuator to the SA...... does the attenuator serve as a dummy load for the radio?  It says it is 50 ohms input and can handle 100 watts.... so I would think so...BUT I can't find a place that discusses it.

Others use samplers.   I have seen some that tap off of the RF on the way to or IN a 50 ohm dummy load.  They just tap resistors off...more or less a voltage divider... and take that point out to the sample port and feed it to the SA.     Is this calibrated enough to allow measurements?  And....the dummy load is dissipating all of the power...and the resistors seem to be high enough that they don't pull a lot of they don't have to be very high powered themselves.   Again, I have found no place to discuss it.

Other people I see use directional couplers.   They seem to be a pass through for the main RF line that you might connect up to a dummy load AND they have a sample port that is some number of dB down.  If the dummy load is dissipating all of the power..... how much power handling does the directional coupler have to account for?   It doesn't seem to me like it would be much..... the dummy load is doing the real work.....but, again, I have found no place to discuss it.

From what I have splattered here.... does anyone know of a resource that offers this kind of info....    I really want to learn what options are for connecting these things up so I don't destroy it on the first go round.

Any ideas?

I would most certainly appreciate it.
New member welcome / Re: Hi to all
« Last post by KE4EST on July 14, 2019, 02:39:12 PM »
Welcome to the forum!!
New member welcome / Hi to all
« Last post by B-Lab on July 14, 2019, 12:47:36 AM »
My name is Bill, live in Easley SC. I am new to forums. I started a shop at my house to work on electronics as a hobby. The interest is repairing vintage electronics such as stereos, hi-fi, amps and Am/Fm radios and so on. Thanks
CB Radio Repair Forum / D201a neutralization question.
« Last post by KK4MSA on July 10, 2019, 11:27:37 PM »
Have a 201a tram here, replaced the electrolytics and high wattage resistors in. Also had to replace the final tube, and I'm following the manual to neutralize and adjusted for -40dc in am and lsb, then it says to retune t700 for maximum dc indication, t700 makes no difference in the -dc at all on the meter, I also have no meter reading in the set/cal position for adjusting the null, it does show rx fine so movement is working, could these 2 issues be related possibly? Is there another way to nutrilize?
Also noteworthy, when meter is hooked to the junction for -dc measurement on the terminal strip, as soon as ac line cord is attached to radio it climbs to about -100ma of -dc.
So have you had any experience with like problem? If so any help is appreciated.
Basic beginner Electronics / Re: EICO 324- BNC for frequency counter
« Last post by kinkydoints on July 09, 2019, 06:08:07 PM »
A question about this eico 324 . all worked out well with the build added a frequency counter -BNC to the unit to double check the count against the dial . On my scope the sine wave is not perfect but does do all the things it should do. OK my question, looking at a QRP kit , in the instructions are some diagrams of this unit called the pixie... for CW on 7.000MHz. on a page is a diagram showing the master oscillator circuit/ colpitts and the "power amplifier circuit"  in this circuit is what is described 
as a "pi-network output filter". for cleaning up the sine wave to the antenna on transmit...or the " key closed " this pi network filter looks fairly simple . would adding a filter to the eico 324's output have the same effect,by cleaning up it's waveform, in theory? might have more to deal with as far as multiple frequencies outputs.?? but if it were tuned for 455Khz. like most if cans ? ya im new at this .
Manuals / Knight KG-670 RC/Tester PDF
« Last post by The Radio Shop on June 01, 2019, 03:04:01 PM »
PDF on the Knight capacitor tester
Test Equipment / Re: SENCORE CB42
« Last post by Crambone on May 25, 2019, 06:53:39 PM »
Ok thank you
Test Equipment / Re: SENCORE CB42
« Last post by The Radio Shop on May 25, 2019, 08:53:54 AM »
Start by checking voltages and AC ripple.  These logic circuits require that the voltage is spot on and clean.
 Also change out any electrolytic capacitors.  At times I have seen the inductors on the counter board go open.
They look like little resistors.
Electronic Video Blog / Re: #119 Sencore CB42 Audio Output Repair
« Last post by The Radio Shop on May 25, 2019, 08:51:10 AM »
I saw your pm today. Been very busy here.
I have yet to get back on working with one of these.  Sometime in the future when time allows.
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