I have a RCA 28X5 mostly restore, but for the following problems. One: When I hook up my outside anntena( 38 ft.long and about 8 ft. off the ground.) to the radio, the auto become very garbled and distortion. But when I don't hook up the outside anntena the auto is fine, also I have a inside anntena when I use that no problem. The garbled and distortion happen on both the am and sw band. When using the sw band the 31 meter band come in with a lot of radio stations, the other meter bands very little pick up of radio stations. AM band works great at any time. Rate now I using a out of the radio speaker because the speaker in the radio is to far go. Does anyone have the right size speaker to go inside the radio or known were I can get one? Thank you.

Hi Bill

Here is a place that sells speakers for old radios:

http://www.oldradioparts.com/2a32fl.txt

Your long antenna is overloading the radio.

The AVC circuit cuts back on strong signals. It will have a .05 or .1 mf cap to ground. If this cap has any leakage strong signals will distort.

Norm

:I have a RCA 28X5 mostly restore, but for the following problems. One: When I hook up my outside anntena( 38 ft.long and about 8 ft. off the ground.) to the radio, the auto become very garbled and distortion. But when I don't hook up the outside anntena the auto is fine, also I have a inside anntena when I use that no problem. The garbled and distortion happen on both the am and sw band. When using the sw band the 31 meter band come in with a lot of radio stations, the other meter bands very little pick up of radio stations. AM band works great at any time. Rate now I using a out of the radio speaker because the speaker in the radio is to far go. Does anyone have the right size speaker to go inside the radio or known were I can get one? Thank you.
:

Different short wave bands will have different amounts of reception, depending on the time of day and the time of year.

Replacement cones are available for most speakers. It is best to keep the original speaker with its radio.

T.

:Different short wave bands will have different amounts of reception, depending on the time of day and the time of year.
:
:Replacement cones are available for most speakers. It is best to keep the original speaker with its radio.
:
:T.Tom that not the problem with the short wave band on the radio. I was using a another radio at the same time I was testing the 28X5, the other radio would pick up a station, 28X5 would not. All I can think of what the problem is on the short wave band of the radio is that it has to have a alignment done to it. Which is bad news, because no one in this part of the state does that kind of work on old radio. To ship the radio out to someone is out of the question. I have been down that road before. So what I may end up doing is look for a new speaker for the radio and just run with the AM band of the radio, which is working great.
:

What is wrong with the speaker?

Does the short wave band pick up anything at all? Does it pick up on one end of the dial and then drop out at the other? (most likely drops out at the high end)

You can obtain fairly inexpensive signal generators from eBay, and do the alignment yourself. If the generator uses mechanical tuning, it might not be extremely accurate. I use my digital all-wave receiver to calibrate the signal generator each time I use it. ...However, unless someone gives you a digital all-wave receiver, they can be somewhat expensive. Try to find a digital signal generator that's affordable, and you will get more accurate results.

If the radio is dropping out at the high end of the dial, the oscillator tube might need replacement.

T.

:What is wrong with the speaker?
:
:Does the short wave band pick up anything at all? Does it pick up on one end of the dial and then drop out at the other? (most likely drops out at the high end)
:
:You can obtain fairly inexpensive signal generators from eBay, and do the alignment yourself. If the generator uses mechanical tuning, it might not be extremely accurate. I use my digital all-wave receiver to calibrate the signal generator each time I use it. ...However, unless someone gives you a digital all-wave receiver, they can be somewhat expensive. Try to find a digital signal generator that's affordable, and you will get more accurate results.
:
:If the radio is dropping out at the high end of the dial, the oscillator tube might need replacement.
:
:T.Tom:Good someone may help me walk though what going on with the radio. The paper part of the speaker has torn into about 2 inchs long(like a knife cut). The shortwave band does pick up some radio stations down in the 31 meter band, like Radio Australia in the morning and China. Between 31 meter band and the 19 meter band all I getting is some Christian radio station, which is all over the place. Question: Is the high end of the dail 19 meters band? If the it yes, the radio does drop out at the high end. I have a digital all wave receiver, it a Grundig 400PE. Will that do? This radio was not the one I was using when testing the 28X5. Does what Norm Leal wrote to me about the AVC circuit add into the mix of what going on?
:

The AVC suggestion applies to distortion.

Before going further, you should check all capacitors for leakage, and replace leaky ones. All paper and mica capacitors should have NO leakage--not even in the 10s of millions of ohms....best checked with a high voltage capacitor analyzer, or just replace them. Mica capacitors are usually good, so don't replace any unless trouble still occurs after all of the paper capacitors have been replaced.

Check all resistors for drifting, especially in the oscillator and power circuits. Check voltages, especially in the oscillator section. Check the oscillator tube for good emissions and function. If still unsure, try another good tube in its place.

In my experience, when the oscillator drops out for short wave, it just goes dead for that section. However, if that Christian radio station is really strong, it might be forcing its way through. That a signal is picked up over a good portion of the dial, with little selectivity, and nothing else around it usually suggests a failed oscillator.

What you would be doing with your digital all-wave receiver is adjusting your signal generator to the frequency you desire according to what your all wave radio says. For instance, if you wanted to inject a 455KC signal to your 28X5, you'd first tune your digital radio to 455KC in the long wave band, and then adjust your signal generator to that frequency so that it came in well on the digital receiver. Then use the signal generator to inject 455KC into your 28X5. Be sure that when you inject the signal into either your digital receiver, or the receiver you're trying to align, that you always use the lowest signal strength possible that can still be received and heard. That way you won't be activating the AVC circuit in either your digital receiver or the receiver you're trying to align.

If the rest of your 28X5 works properly, and stations come in where they should, assume, first, that the radio is already properly aligned, and look for other trouble. Don't attempt to align the short wave band until you are sure that the radio is functioning properly in the first place.

According to the literature for your radio, your speaker uses a standard 4 ohm voice coil, and the cone measures 6 x 9 inches. These cones are readily available, and can be fitted to your voice coil. Also, 6 x 9 4 ohm speakers are readily available new. However, due to different magnet construction, they might not fit your radio. It is best to try to recone your speaker, first.

T.

:The AVC suggestion applies to distortion.
:
:Before going further, you should check all capacitors for leakage, and replace leaky ones. All paper and mica capacitors should have NO leakage--not even in the 10s of millions of ohms....best checked with a high voltage capacitor analyzer, or just replace them. Mica capacitors are usually good, so don't replace any unless trouble still occurs after all of the paper capacitors have been replaced.
:
:Check all resistors for drifting, especially in the oscillator and power circuits. Check voltages, especially in the oscillator section. Check the oscillator tube for good emissions and function. If still unsure, try another good tube in its place.
:
:In my experience, when the oscillator drops out for short wave, it just goes dead for that section. However, if that Christian radio station is really strong, it might be forcing its way through. That a signal is picked up over a good portion of the dial, with little selectivity, and nothing else around it usually suggests a failed oscillator.
:
:What you would be doing with your digital all-wave receiver is adjusting your signal generator to the frequency you desire according to what your all wave radio says. For instance, if you wanted to inject a 455KC signal to your 28X5, you'd first tune your digital radio to 455KC in the long wave band, and then adjust your signal generator to that frequency so that it came in well on the digital receiver. Then use the signal generator to inject 455KC into your 28X5. Be sure that when you inject the signal into either your digital receiver, or the receiver you're trying to align, that you always use the lowest signal strength possible that can still be received and heard. That way you won't be activating the AVC circuit in either your digital receiver or the receiver you're trying to align.
:
:If the rest of your 28X5 works properly, and stations come in where they should, assume, first, that the radio is already properly aligned, and look for other trouble. Don't attempt to align the short wave band until you are sure that the radio is functioning properly in the first place.
:
:According to the literature for your radio, your speaker uses a standard 4 ohm voice coil, and the cone measures 6 x 9 inches. These cones are readily available, and can be fitted to your voice coil. Also, 6 x 9 4 ohm speakers are readily available new. However, due to different magnet construction, they might not fit your radio. It is best to try to recone your speaker, first.
:
:T.Tom: Thank you for taking time to help me out and on passing the information on how to fix my radio. Bill Quinn
: