524 not transmitting

[tbanks]

Gee Ray thanks for the plug....I think.Diagnosing these radios in a shop with all the test equipment is hard enough but trying to do it via postings or email is really tough.The problem could be as simple as a bad cable or other componet or as bad as a catostrophic melt down.If your buddy has a known working radio I would first put his radio in your truck to make sure you dont have a problem with your mount or cabling.If it all works you may want to check the high voltage circuit breaker inside the radio to make sure its not tripped.
As my former boss was fond of saying "these radios are all surplus,made from parts up to 40 years old,manufactured by the lowest bidder and one throw of the switch away from failure".
Most guys buy these sets from a guy who swears they work.Let me say there is "working" and there is working.Turning it on and hearing static does not always mean it works.
The company I worked for charged 75.00 per hour shop time to trouble shoot and repair the VRC12 series stuff.I have seen the techs work for days on sets sent in by other companies.

[mgtrooper]

Sir

Where might that circuit braker be? I will check it.

Steve

[mgtrooper]

Happy easter everyone.

I wanted to give an update to my 524. While I am waiting to get money together to make or purchase the proper mount for my 6707, I have mounted my AB-15 on my M38A1. My friend Rich who has an M38 has the same set up. We powered up our radios yesterday and had successful transmission and receiving on both radios. First at relatively close range then up to 10 miles away from my house to his. We did find that at long range past about 3 miles the jeeps needed to be running, other wise they did not have the power to transmit very far. We use three masts 116 117 118 on the AB-15 and were transmitting on 30/ 30 to stay out of anyone's way. We are both going to get our ham license to be on the up and up even though it will be rare that we use the commo.

Thanks for everyone input here.

Steve

[Rainman]

Hey MGT,
Here's a site that may help if you plan on jerry-rigging your radio's antenna system...
http://www.csgnetwork.com/antennageneri ... ncalc.html . You should include the length from the top of the AB-15 ceramic insulator to the tip of your antenna. Looks like you had close to 122 inches of effective antenna during your test. (not good) Using AB antenna sections will give you more options with mix and match of the shorter antenna element lengths.
Rainman

[rickf]

I am not an expert on military radios but I was always told the AB-15 and associated sections was a receive only set-up. If I am wrong someone will correct me, if I am right you are taking a chance of burning the finals in your radio. At ten miles you had to be on high power.

Rick

[moose53]

The AB-15 was used receive only just with the VRC-12 radios, because the frequency range was so broad they developed antennas with matching circuits for the RT's. Prior to that starting in the 1940's, AB-15's were used for transmitting also. The frequency bands on the older radios were narrow enough that they could be matched just by using the correct combination of various antenna elements to create the proper length antenna.

Jim

[Rainman]

As Moose has said, the AB-15 antenna base with antenna sections M116, M117, M118, AB21, AB22, AB23, and AB24 is capable of trouble free transmitting, so long as it is tuned for the proper transmit frequency. The best example would be CB radio. Known as 11 meter CB band, it was on high 26. MHZ thru mid 27 MHZ freq. The mobile antenna used by all CB'rs was the 102" whip. Plug that into the calculator and you can see the correlation as a 1/4 wave antenna match for the 11 meter band. The 11 meter band also has a sign wave of 11 meters in length hence "11 meter band". The 6 meter band is covered by the RT-524 and is most often used by MV hobbyists on freq 50 MHz to 54 MHz. Halfwave antenna length of 6 meter band would be a 3 meter antenna or quarterwave of 6 meter band being 1.5 meter length. If your not tuned on the transmit freq especially on high power, you will fry your radio's final output transistors no ifs, ands, or buts. RT'524's may handle a little abuse, but they're 30 to 50 yrs old now. Playing with radios is lots of fun. Making the smoke come out of them not so much.
Rainman

[mgtrooper]

Ok.

I hear you. No more transmitting with the AB-15... receive only. I am content for now to know that the VRC 524 receives and transmits. Yes we were on high power at 10 miles. I take it that low should have been enough. My understanding of the antenna length and frequency is limited to: 2 sections are infantry and 3 are artilery.

[mgtrooper]

http://i1233.photobucket.com/albums/ff3 ... G_0714.jpg


I just wanted to post a photo of my M38A1 with the 524. I am going to put together a mount for the 6707 before I transmit any more. I have heard enough counsel that these radios work better communicating via transmiting radios wave than smoke signals.

[rickf]

That is a nice 38 and some beautiful country!

Rick

[UeS]

Hi there.
I have a problem with the 524.
Radio receives great but there is no transmission. Range only within 5 meters from the MUTT.
I checked the switch to X mode. Is set to NORMAL.
During transmission scratchy in both handset and speaker and the receiver 524 77th The quality of broadcasting bad. 524 Receives great.
Frequency switch does not have a full range of both ranges.
524 only runs at full frequency, for example. 30.000 MHz. The 30 025 is not.
Aena works and sets the base of the same radio frequency in both ranges.

I tried to replace the antenna on the regular cable ... works the same way.

[Rainman]

Ues,
What are you using as the test receiver to listen to the 524? Do you have access to any test equipment. ie: wattage output meter?
Rainman

[UeS]

How did the test?? I pressed the PTT 524 and listened to the 77
I have some test stuff at work. But not for use at home. I had to pull MUTT 500 km. I have no time for the month of going to your guys into a far country "A";)
I'll do photos inside the 524 next week and paste here.
There was a white wire in the middle of the circle X-MODE switch disconnected. Joined it. 524 unchanged.

Another problem.
I have this set: http://images.google.com/imgres?q=r+442 ... 2,s:0,i:81

R442 lamp is lit, the frequency range lights, hear the noise, there is no transmission, no receiver
I do not know if I have all the cables to the set??

1077 on the platform of the car receives. The backpack does not answer. transmiting well.

That is just my old 77 works flawlessly.

[Rainman]

Hi UeS,
I now understand your are testing your RT-524 with a PRC-77. I'm having trouble understanding , possibly just a language barrier. Perhaps the pictures will assist.
Rainman

[UeS]

OK. Here are the promised pics ...
1. My set at MUTT



2. antenna base


3. Slots in the fundamentals of radio. I only have the power cables
442


524


4. 524 upper side. Cable P6001 from J6101 to J6001 was unplugged


I plugged it and now 524 has increased range to 50 meters on low end xxx meters on high. The quality of broadcasting is the average

5. I have a problem with this ...

because...the range of settings on the switch frequency at the lower ends of the...

...the upper range of...


6. 524 down side


7. R 442 upper side


P1005 cable was connected to the J1002
I plugged it into the J1005.

R-442 does not transmit or receive. The lamp is light...


8. switch position


9. Down side


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