I have a older signal generator WR 50A by RCA. I verified output signal on a new AM/FM tuner (can't test shortwave MC's). Quite accurate from 530 KC upward.
Digital multimeter.
Non conductive alignment tools.
What is the best way to verify alignment? Just use good ear? A VU Meter (where do I get one if needed)? I am used to the older radios which seem to be a lot more tolerant.
Thanks
Jeffrey
To proceed with the shortwave bands, you will need to verify the calibration of your signal generator at 6.1, 9.6, 11.8, 15.2 and 17.8MC. To do this you need to check it against a shortwave receiver, or better yet buy a frequency counter which you can hook up to your signal generator for use on all frequencies. But do the IF and AM alignment first--you may be surprised how much improvement you get.
Poston
:What is the best way, short of using expensive devices, to align radios such as Trans Oceanics? I understand that alignment accuracy at the beginning can effect the subsequent adjustments.
:
:I have a older signal generator WR 50A by RCA. I verified output signal on a new AM/FM tuner (can't test shortwave MC's). Quite accurate from 530 KC upward.
:Digital multimeter.
:Non conductive alignment tools.
:
:What is the best way to verify alignment? Just use good ear? A VU Meter (where do I get one if needed)? I am used to the older radios which seem to be a lot more tolerant.
:
:Thanks
:
:Jeffrey
:
I will fire up an old analog triplett meter I have around here and dial in again, thus avoiding any ear error.
Thanks for the suggestion and I will look for a frequency meter. Any other suggestions are appreciated as well.
Jeffrey
:Hi Jeffrey,
:The first step (and the most important) is to align the IF transformers to the T-O's intermediate frequency (455kC), then proceed to the tuning condenser trimmers at 1600kC and 1400kC. Follow the alignment instructions as per the service literature. Your RCA WR-50A signal generator will work fine for this if you have verified its accuracy in the kC range. In addition to your signal generator you will need an AC voltmeter to use as an output measuring device across the speaker voice coil. An analog meter is best, so that you can watch the needle and adjust for maximum deflection. A VTVM is preferred, but any decent analog VOM will work.
:
:To proceed with the shortwave bands, you will need to verify the calibration of your signal generator at 6.1, 9.6, 11.8, 15.2 and 17.8MC. To do this you need to check it against a shortwave receiver, or better yet buy a frequency counter which you can hook up to your signal generator for use on all frequencies. But do the IF and AM alignment first--you may be surprised how much improvement you get.
:
:Poston
:
:
:
::What is the best way, short of using expensive devices, to align radios such as Trans Oceanics? I understand that alignment accuracy at the beginning can effect the subsequent adjustments.
::
::I have a older signal generator WR 50A by RCA. I verified output signal on a new AM/FM tuner (can't test shortwave MC's). Quite accurate from 530 KC upward.
::Digital multimeter.
::Non conductive alignment tools.
::
::What is the best way to verify alignment? Just use good ear? A VU Meter (where do I get one if needed)? I am used to the older radios which seem to be a lot more tolerant.
::
::Thanks
::
::Jeffrey
::
Let the radio and signal generator operate for at least 20 minutes before you make any adjustments.
Also, there are a number of "marker frequencies" that you may find very useful, and you may also reveal a nonlinear portion of the tuning dial in the process.
WWV Operates on 2.5, 5.0, 10.0, 15.0, and 20.0 MHZ, Although propagation conditions may have an effect on how well you will hear these during the day.(US)
CHU Operates on 3.330, 7.335, 14.670. (Canada)
Both have similar time code interval signals, but CHU announces in French and English. Again, Propagation may affect how well you hear them.
When you have one of these signals at an extreme end of the band, you can actually just use it for alignment purposes. But you will still want to go back and forth with each band starting from the lowest, to get as close to accurate and linear as you can.
There will also be times when you have to simply accept a compromise in the accuracy for uniformity on the band too.
:Hello Poston,
:In fact, I have done the IF as well as the condensor trimmers at 1600 & 1400 kc. As you say, there is a marked improvement even using my ear to tune. I even did the padder adjustment on C32 at 600KC. However, when I get to the MC adjustments, I can get the upper dial adjust settings for 7.8, but can't get the spread down to the 4.2 by adjusting the 4-8 oscillator coil slug. Seems like I can get down to around 4.8 or 5 (moved the sig gen to get audible at 4.2 dial setting and it read 4.8). Then I go back to the 7.8 readjust, and can't get that either. Seems like the target is moving on me. Radio has new capaciors, new resistors (most), good tubes, correct filament voltages.
:
:I will fire up an old analog triplett meter I have around here and dial in again, thus avoiding any ear error.
:
:Thanks for the suggestion and I will look for a frequency meter. Any other suggestions are appreciated as well.
:
:Jeffrey
:
::Hi Jeffrey,
::The first step (and the most important) is to align the IF transformers to the T-O's intermediate frequency (455kC), then proceed to the tuning condenser trimmers at 1600kC and 1400kC. Follow the alignment instructions as per the service literature. Your RCA WR-50A signal generator will work fine for this if you have verified its accuracy in the kC range. In addition to your signal generator you will need an AC voltmeter to use as an output measuring device across the speaker voice coil. An analog meter is best, so that you can watch the needle and adjust for maximum deflection. A VTVM is preferred, but any decent analog VOM will work.
::
::To proceed with the shortwave bands, you will need to verify the calibration of your signal generator at 6.1, 9.6, 11.8, 15.2 and 17.8MC. To do this you need to check it against a shortwave receiver, or better yet buy a frequency counter which you can hook up to your signal generator for use on all frequencies. But do the IF and AM alignment first--you may be surprised how much improvement you get.
::
::Poston
::
::
::
:::What is the best way, short of using expensive devices, to align radios such as Trans Oceanics? I understand that alignment accuracy at the beginning can effect the subsequent adjustments.
:::
:::I have a older signal generator WR 50A by RCA. I verified output signal on a new AM/FM tuner (can't test shortwave MC's). Quite accurate from 530 KC upward.
:::Digital multimeter.
:::Non conductive alignment tools.
:::
:::What is the best way to verify alignment? Just use good ear? A VU Meter (where do I get one if needed)? I am used to the older radios which seem to be a lot more tolerant.
:::
:::Thanks
:::
:::Jeffrey
:::