One of my customers had a relative visit from Mexico. They brought this modified Uniden PC68 and an amplifier for me to check out and give my opinion.
Apparently, this stuff is readily available down there. I haven’t seen an amplifier that claimed a 120-watt peak output this small before.
Very skeptical, I put it on the bench and connected it to my meters and dummy load. The radio alone only put out under a half-watt dead key with a modulation swing of 5 Watts.
With the amplifier on, the dead key was 21 Watts with a swing to 120 Watts peak. Wondering how it sounded, I tuned my Kenwood R5000 receiver to the same frequency and monitored the audio.
To my amazement, it sounded very clean. Checking it on the scope showed some squaring of the audio sine wave but nowhere near what it would be if the radio AMC was clipped. Curious, I turned down a Uniden Grant to 6 Watts PEP on the sideband and connected the Turbo. It pumped out 135 Watts and sounded clean.
Although time ran out before I could open it and take photos, they told me that there is a potentiometer for setting the relay un-key delay inside the amp. This amp has a receiver preamp. It had marginal results on the PC68.
I imagine it would help when the channel was quiet, but the test was done during the day when the skip was at its peak. Although a low gain preamp, it didn’t introduce any noticeable noise or distortion when a low-level signal was injected with a signal generator.
A quick test on the Grant radio didn’t show any noticeable change with the preamp on or off. Although the preamp didn’t really impress me, the output power and clarity did to the extreme.
They didn’t know where the amplifier was produced; they thought it was manufactured in Mexico but couldn’t be sure.
The store owner was protective of any information about these products. In fact, they told me that a customer couldn’t just walk into the store and buy one. The amp had to be matched to a radio before it left the store.
Either you brought a radio in to be setup, or you bought on off the shelf, and the store owner set them up together before you left. This is understandable because of the very low power requirement to drive the amp to full output.
A stock CB radio would burn it out and sound awful for the minute or two before it fried.
We think we have access to everything in this country, but I haven’t seen this one before. Its small size would make it popular for many applications.
Even Ham operators would like to have extra power on 10 meters, which doesn’t take up much space. It only draws 12 Amps on the sideband and about six on AM.
If it were used on FM, I would only recommend 40 Watts in that mode for any length of time. The heatsink isn’t large enough for continuous full power.
When they left my store, they hooked up the radio and gave me a shout. Once again, the performance was impressive. The signal cut through the skip cleanly 5 miles away.
I took a little ribbing about how they had access to them, and I didn’t. Several other drivers jumped in to find out what they were running and gave their compliments.
Quite a setup; it’s not competition class, but very impressive just the same. I thought they knew what my impression was going to be before they brought the stuff in for me to check.
What is the Uniden PC68XL Turbo 121?
The Uniden PC68XL Turbo 121 is a modified Uniden PC68 radio that comes with an amplifier. The amplifier claims a 120 Watt peak output, which is quite high for its small size.
How does the Uniden PC68XL Turbo 121 perform in terms of output?
When tested, the radio alone put out under a half Watt dead key with modulation swing to 5 Watts. With the amplifier on, the dead key was 21 Watts with a swing to 120 Watts peak. The output power and clarity were impressive.
How does the Uniden PC68XL Turbo 121 sound?
The Uniden PC68XL Turbo 121 provides very clean audio. Even when the audio sine wave exhibited some squaring, it was nowhere near what it would be if the radio AMC was clipped.
What is unique about the amplifier that comes with the Uniden PC68XL Turbo 121?
The amplifier that comes with the Uniden PC68XL Turbo 121 has a receiver preamp. Although the preamp had marginal results on the PC68, it didn’t introduce any noticeable noise or distortion when a low-level signal was injected with a signal generator.