Help needed - KL503HD DK 160 watts with 2 watt Radio DK?

[Eldorado828]

I'd be thinking the 5000 plus is a little hot for the 503hd unless you do a little de-tuning. The input padding on the 503hd seems to not be enough for the dual final export. That radio has a lot of swing even turned down as it sits. You'd need to do some internal adjustments and see where you can get the low dk but still get some swing to no more than about 30 pep into the box. Just because it's a high drive amp doesn't make it a simple plug and play match, there's some input specs you have to adhere to. Not sure as to tune on the radio but if you mix dirty on top of too much powa and you're increasing the possible problems.

 

[Mustang950]

My opinion is you are focusing too much on PEP. You reach the PEP when your voice is the loudest and/or you whistle into the mic, but people don't usually talk at the PEP level. Ask the seller what the recommended dead-key for that amp is. As I stated before, using an amplified mic with a ten-meter radio plus an external amp may not be good for the radio. Maybe the person / shop who converted the radio to eleven-meters can adjust / reduce the dead-key. There should be an instruction sheet with the amp which indicates the maximum input watts.

The radio dead key is adjustable from 1.5 - 12 watts.
After much reading my understanding was that the amp input limit of 35w was the sum of DK/carrier and swing.
Attached is the AMP Manual.
Some things that apply:
"Before the amplifier is switched on, switch , the power output of the drive radio should be adjusted correctly if it is capable of outputting a power greater than 25W. This may be done with the amplifier connected but switched off. 35W is the maximum permissible input power to the amplifier, but approximately 25W input should be sufficient to realize full output, and an input power of 2-25W is OK as it is not necessary to run the amplifier at full output if not required."
I'm not looking for you to provide all the answers but I do appreciate your advice/input.
Thanks again for the help.

 

[Mustang950]

I'd be thinking the 5000 plus is a little hot for the 503hd unless you do a little de-tuning. The input padding on the 503hd seems to not be enough for the dual final export. That radio has a lot of swing even turned down as it sits. You'd need to do some internal adjustments and see where you can get the low dk but still get some swing to no more than about 30 pep into the box. Just because it's a high drive amp doesn't make it a simple plug and play match, there's some input specs you have to adhere to. Not sure as to tune on the radio but if you mix dirty on top of too much powa and you're increasing the possible problems.

Understand,
I was thinking since I could adjust the DK out of the export radio to the point where PEAK was 200-250 out of the AMP and it ran cool I would be OK. I will also try the AMP with my Uniden 980 which doesn't swing nearly as much and the export. The export DK is front panel adjustable only as it has no internal adjustments. The 980 DK is easy to adjust internally so I will give it a try and see if it will drive the amp.
It seems possible I have already damaged the amp attenuator with the export radio with the little testing I've done so far and that may be why it works on only the high setting.
Thanks for the input, much appreciated.

 

[Mustang950]

My opinion is you are focusing too much on PEP. You reach the PEP when your voice is the loudest and/or you whistle into the mic, but people don't usually talk at the PEP level. Ask the seller what the recommended dead-key for that amp is. As I stated before, using an amplified mic with a ten-meter radio plus an external amp may not be good for the radio. Maybe the person / shop who converted the radio to eleven-meters can adjust / reduce the dead-key. There should be an instruction sheet with the amp which indicates the maximum input watts.

I didn't completely answer your questions in my other post.
My focus on PEP is/was to prevent exceeding the 300w output rating of the AMP. I do realize my meter likely does not indicate true peak/PEP so my goal was 250w vice the AMPs max of 300w. The export is a new model and the conversion to 11 meter is done on the front panel by the user=me. Multiply reviews of the radio and internal photos indicate there are no internal adjustments possible.

 

[Recon]

It sounds as though the radio's dead-key cannot be adjusted below 1.5 watts. Am I correct?

Why a "cheap" amp? Why would you buy a decent radio and amp and use low grade test equipment?
Would you install a new tire on a bent wheel?

 

[Mustang950]

My thought process:
- This is CB, not HAM and I have self imposed budget limits.
- I've had good luck with RM Italy KL-60 (30 watts) and KL-203 (100 watts) AMPs when paired with stock Unidens with a DK adjustment and slight modulation adjustment. So I thought the 503High Drive was a reasonable step up since I was moving the 203 to my mobile.
- I wanted to upgrade to this 10 meter because of it's noise cancelling feature, reasonable power output, and reports of clean, clear output and other features. With it's DK adjustability, I thought it could work within the specs of the 503HD. Based on the power outputs I am seeing this seems to be the case.
- The Meter; DAIWA 901-HP was highly recommended here as a user meter for maintaining home equipment. But my understanding is that a Bird with a PEP kit, properly calibrated, is the "standard" for true power (Peak/PEP) measurement and other meters are likely only representing +/- 20% of the actual value. I could be wrong here.
Anyway, thanks for the help thus far.

 

[Recon]

My thought process:
- This is CB, not HAM and I have self imposed budget limits.
- I've had good luck with RM Italy KL-60 (30 watts) and KL-203 (100 watts) AMPs when paired with stock Unidens with a DK adjustment and slight modulation adjustment. So I thought the 503High Drive was a reasonable step up since I was moving the 203 to my mobile.
- I wanted to upgrade to this 10 meter because of it's noise cancelling feature, reasonable power output, and reports of clean, clear output and other features. With it's DK adjustability, I thought it could work within the specs of the 503HD. Based on the power outputs I am seeing this seems to be the case.
- The Meter; DAIWA 901-HP was highly recommended here as a user meter for maintaining home equipment. But my understanding is that a Bird with a PEP kit, properly calibrated, is the "standard" for true power (Peak/PEP) measurement and other meters are likely only representing +/- 20% of the actual value. I could be wrong here.
Anyway, thanks for the help thus far.

I apologize! I meant to write, "why a cheap amp meter.
Food for thought!
I have the DAIWA CN-901 HP3 meter which I use as a "guide", but I have two BIRD wattmeters for accuracy.
The BIRD Model #4410A with the 4410-4 element would be a good wattmeter to start off with. I also have the Model #43 with several elements. The cost of each element is about $200.00, and the cost adds up fast.
I damaged a new KL203P amp by connecting a new out of the box stock President Bill 4-watt radio to it. Apparently, the radio had too much swing going into the amp. I have learned a valuable / expensive lesson.
I recently bought another President Bill for my truck. I had the dead-key reduced down to two-watts, and it is connected to a KL 203 with no problems.
The BIRD #4410A meter can be turned off to conserve the battery. It also has a battery level mode to monitor the strength of the battery.
The BIRD #43 has two batteries and the PEP kit. If you forget to turn off the PEP function, the batteries will drain because of the ON / OFF pilot light. Weak batteries on any meter will give you false readings.

 

[Mustang950]

I apologize! I meant to write, "why a cheap amp meter.
Food for thought!
I have the DAIWA CN-901 HP3 meter which I use as a "guide", but I have two BIRD wattmeters for accuracy.
The BIRD Model #4410A with the 4410-4 element would be a good wattmeter to start off with. I also have the Model #43 with several elements. The cost of each element is about $200.00, and the cost adds up fast.
I damaged a new KL203P amp by connecting a new out of the box stock President Bill 4-watt radio to it. Apparently, the radio had too much swing going into the amp. I have learned a valuable / expensive lesson.
I recently bought another President Bill for my truck. I had the dead-key reduced down to two-watts, and it is connected to a KL 203 with no problems.
The BIRD #4410A meter can be turned off to conserve the battery. It also has a battery level mode to monitor the strength of the battery.
The BIRD #43 has two batteries and the PEP kit. If you forget to turn off the PEP function, the batteries will drain because of the ON / OFF pilot light. Weak batteries on any meter will give you false readings.

Recon,
No harm, no foul. All good.
I have a lot to learn.
I did some more testing this morning.
Uniden 980 2w DK results in 35w DK out of AMP, 200w PEP. 11.5 amp draw to the AMP.
DX5000Plus - 2w DK results in 35w DK out of AMP, 250PEP, 16.5 amps draw to the AMP.
The paperwork for the AMP states full output should be achieved with about 25W input. So I think I have a safe margin?

One thing that is confusing to me, the DK amp draw is within 1 AMP of the modulated AMP draw? DK 35w, Modulated 250w seems like amp draw would go up significantly, even proportionally?
Thanks again for everything.
Now if I can just keep the magic smoke inside the AMP! lol

Edit, more confused now because with the same DK not modulating the AMP draw is different, 11.5 amps for the 980 vs 16.5 for the DX5000.
Ugh!

 

[Recon]

Recon,
No harm, no foul. All good.
I have a lot to learn.
I did some more testing this morning.
Uniden 980 2w DK results in 35w DK out of AMP, 200w PEP. 11.5 amp draw to the AMP.
DX5000Plus - 2w DK results in 35w DK out of AMP, 250PEP, 16.5 amps draw to the AMP.
The paperwork for the AMP states full output should be achieved with about 25W input. So I think I have a safe margin?

One thing that is confusing to me, the DK amp draw is within 1 AMP of the modulated AMP draw? DK 35w, Modulated 250w seems like amp draw would go up significantly, even proportionally?
Thanks again for everything.
Now if I can just keep the magic smoke inside the AMP! lol

Sorry, but I do not have any technical knowledge to help you with amp draw and etc. I admit that I am a "street smart" guy and I know my limitations.
Just like the song, The Gambler! You have to know when to hold them and you have to know when to fold them!
I agree with Eldorado828. I think your radio is too "hot" for what you want to do because there is minimum space for operator error. I've had several converted export ten-meter radios with variable RF power capabilities, and I had the dead-key set to 3/4 watt.
You will be surprised on how far your radio will reach-out with less than three-hundred watts, base or mobile. I have a two-pill feeding a ten-pill. For the past five days, I've only been using the two-pill when talking skip and the same guys I communicate with have not noticed any difference.

 

[Recon]

Recon,
No harm, no foul. All good.
I have a lot to learn.
I did some more testing this morning.
Uniden 980 2w DK results in 35w DK out of AMP, 200w PEP. 11.5 amp draw to the AMP.
DX5000Plus - 2w DK results in 35w DK out of AMP, 250PEP, 16.5 amps draw to the AMP.
The paperwork for the AMP states full output should be achieved with about 25W input. So I think I have a safe margin?

One thing that is confusing to me, the DK amp draw is within 1 AMP of the modulated AMP draw? DK 35w, Modulated 250w seems like amp draw would go up significantly, even proportionally?
Thanks again for everything.
Now if I can just keep the magic smoke inside the AMP! lol

Edit, more confused now because with the same DK not modulating the AMP draw is different, 11.5 amps for the 980 vs 16.5 for the DX5000.
Ugh!

I have read a few reviews about your radio. The dead-key cannot be reduced and there is a good chance the lowest dead-key is 2-1/4 to 3 watts.

 

[Mustang950]

I have read a few reviews about your radio. The dead-key cannot be reduced and there is a good chance the lowest dead-key is 2-1/4 to 3 watts.

Reviving this thread just in case anyone is interested. The DK is adjustable in the service/maintenance menu. I have the DK range set from .5 - 12w. I have been running the radio with the 503HD for about a year now with no problems/damage or overheating. In the past few months I have been using FM and discovered it is easy to overdrive (exceed the DC input amps) the 503. I use a DC current in monitor on the 503 and keep the input amps to 30 max and normally 25. The DX5000 Plus, 503HD amp and MACO V58 antenna has been a great combination for both local and skip.
73s - 950/Mustang

 

[9C1Driver]

Things also warm up very fast when talking FM. For FM maybe try running the amp on setting 3-4, then have the FM output from the radio at 3-5 watts and see where your at. The amp could probably do well on FM at 70-120 watts. You can mess around with input and amp settings to see what looks the best. A fan might also be a good idea if you get long winded.

(and as you probably already know remember on FM there is no swing on the meter, it's all carrier)

 

[Mustang950]

9C1Driver, thanks. I do/have always run a fan on the 503 and occasionally monitor it's temp with an IR thermometer and it has never gone above maybe 100F. Yes the no swing FM was new to me when I started but chatting with the UK guys they helped me out. Right or wrong?/ I feel confident monitoring the DC supply current to the amp as a way to limit it on FM. I also use DC supply current when using it on AM but limit it to 15amps as I think my DC monitor only gives me DK amp draw and not swing? I'm guessing seeing swing amp draw would be so transient my DC amp meter won't see it?
Hopefully I'm not out to lunch monitoring DC input amps?
Thanks again,

 

[Robert Cook Sr]

Hello all,
I need help with a new 503HD. It DK keys at 160 watts with a 2 watt radio DK.
- I'm using a DAWIA 901HP meter set on Peak 200w or 2000w setting.
- No indication of swing.
- Radios used; K-PO DX5000 plus set at 2w DK (tried with 1-4w DK results the same), swings to 18-20w on my meter. Uniden 980 slight modulation adjustment, 2w DK, swings to 8-10 w. The results are the same for both radios=160w DK out of the AMP with no indicated swing.
- Using the 980 with a KL203 results in 25w DK out of amp with Peak of 110w with meter in peak/hold. SO this tells me the meter should function to indicate swing with the 503.

Any ideas why the 503 DK is so high out of the amp with a 2 W DK in?
The amp is new/received it a few days ago.
I will be contacting the seller later in the day.
Thank in advance for any assistance.
David

the 503HD uses from 5-35 watts to drive it. I use dead key of 8 watts and get around 90 watts dead key Pep is around 35 watts input and 250-300 watts output with 1.2SWR. Also I'm using a 5555N11 radio to drive it. My 980 uniden doesn't drive to good with a 3.5 watt dead key and low modulation. I also use a D104 power mike desk top.

 

[Robert Cook Sr]

the 503HD uses from 5-35 watts to drive it. I use dead key of 8 watts and get around 90 watts dead key Pep is around 35 watts input and 250-300 watts output with 1.2SWR

Thats using #4 setting for output of 503HD which is a high drive unit ,I have 3 of them and 1 low drive unit 503