Anytone Anytone D-578v UHF to VHF crossband problem

[K0AAJ]

I recently purchased the 578 and I need to crossband from my UHF ht to a VHF simplex frequency.

I have the channel A set as repeater to the VHF frequency and the sub channel B set to the UHF frequency. The problem is the audio level listeners receive on the VHF side is noticeably lower than needed. I am using a Diamond X-700 Dual band antenna atop my 40’ tower and transmitting on the VHF side at turbo and my ht is set at 1watt, which should be fine just under the tower. I’ve tried increasing mic gain from the ht and tried multiple HT’s with the same results.

Has anyone experienced this with the 578? Am I missing something in the set-up?

Thanks for any help.

 

[K0AAJ]

UPDATE: I measured the wattage output from the VHF side of the repeated UHF signal and the signal level is half the normal output without the repeater function. My meter indicates the wattage of the normal channel output to be 53 watts when configured for Turbo.
The repeated wattage measures 23 watts regardless of the channel B power setting. This is pitifu.

 

[chief21]

Is this analog-to-analog or is DMR involved? It also appears that you've contradicted yourself as to which side (A/B) is VHF and which is UHF. Please confirm the signal flow.

 

[K0AAJ]

It‘s A-to-A. Pretty simple... A-VHF, B-UHF
I’m now thinking it is a power level drop, since I’m dealing simplex to the world with no FM repeater to repeat.

 

[KE5MC]

Received audio level is more about deviation than power on analog which will get scratchy as you move away. Digital... one moment its there and the next its gone...

 

[K0AAJ]

Thanks. I fairly sure the radio is a goner..... I’m selling it.

 

[KE5MC]

UPDATE: I measured the wattage output from the VHF side of the repeated UHF signal and the signal level is half the normal output without the repeater function. My meter indicates the wattage of the normal channel output to be 53 watts when configured for Turbo.
The repeated wattage measures 23 watts regardless of the channel B power setting. This is pitifu.

The 578 does seem to have a love/hate following and if its a goner, understood.

There has been much discussion on DMR radios and using which time slot or both and repeater mode or simplex. I don't recall the details of the many discussion several months ago. My first DMR handheld surprised me when I measured its output on a dummy load using an Elecraft electronic wattmeter with the appropriate coupler. Meter was in average mode and I got 2.5 watts expecting 5. Switched to peak and get the 5 I had set the radio for. Transmitting on only one time slot was new to me and the measurement results. It could be your 23 watts is correct for an average reading wattmeter in a one time slot only transmission. I'm surprised changing the power setting had no effect. There have been "bugs" corrected from the first release in software and I seem to recall they were about cross-band repeating. Not the best position to be in as beta tester for production hardware. :-(
Good Luck
Mike

P.S. Likely some push back on choice of words relative to wattmeters. "Average-Peak-RMS" Point is meters are only as good as how we use and apply them.

 

[K0AAJ]

Thanks Mike. I thought checked both peak and average, but point well taken! I’ll try my dummy load also.

73

 

[K0AAJ]

I measured SWR at 1.2 on the meter into the dummy load and 40 watts output with repeater off. I measured 22 watts into the dummy load repeater on. No appreciable difference between peak and a average. My meter is a MFJ-873. Not the best, but it’s what I have to work with.

With all that being done, the repeater output Is low and my audio is low. I guess I need to go back and check the notes from the past firmware changes.

73

 

[chief21]

I measured SWR at 1.2 on the meter into the dummy load and 40 watts output with repeater off. I measured 22 watts into the dummy load repeater on.

I haven't read anything from others regarding this and I haven't played with the cross-band function on mine, but I'm wondering if the power drop is intentional in order to prevent frying the finals when operating cross-band into a repeater (high duty cycle).

Did you measure the output on the UHF side? Does it do the same thing?

 

[K0AAJ]

Well you brought light to a parameter I haven’t considered..... the radio is rated at 40W max for UHF. This could be part of the reason, but I have the B channel, which is the link to the UHF ht frequency. I never push the input receiver side wattage, so I started a 1 watt for the channel power parameter. Makes my head hurt So I’m throwing in the towel.

73

 

[WA0CBW]

How are you measuring power? DMR can be measured with a standard watt meter but the reading will be incorrect as the radio does not transmit continuously. Remember 30 millisecond pulses including a 2.5 millisecond listening silence for each frame. This works out to about 60% RF out and 40% no RF output for each PTT.

 

[K0AAJ]

This is all analog crossband. No DMR involved.

73

 

[WA0CBW]

Me thinks I should read more closely and slower

 

[K0AAJ]

Hahaha!

 

[TassieJay]

Halving the RF output power in any-mode-to-any-mode crossband is normal, intentional, and by design. The engineers said the radio isn't designed for near 100% duty cycle TX, which is exactly the sort of thing that could be expected to happen when a radio is put into crossband repeat mode, hence the power reduction to protect the electronics from cooking itself. If you want a repeater that works at full 50-100 watts output power, buy a real repeater.

 

[K0AAJ]

Thank you for your comment, but based on the fact that my ht is set for 1 watt, my UHF channel is set for 1 watt output, and the VHF channel is set for Turbo.... halving the VHF output wattage doesn’t make sense even for less than 100% duty cycle. I will verify your comments with a V71 Kenwood, which I know gets very hot if the tx is help for long periods.

 

[tweiss3]

Just looking at the manual and saw this disclaimer:


Did you make sure to turn off the digital monitor?

 

[a417]

Cheaper to fix it in the PDF than to make sure the firmware does it at the hardware level.

 

[KE5MC]

Thank you for your comment, but based on the fact that my ht is set for 1 watt, my UHF channel is set for 1 watt output, and the VHF channel is set for Turbo.... halving the VHF output wattage doesn’t make sense even for less than 100% duty cycle. I will verify your comments with a V71 Kenwood, which I know gets very hot if the tx is help for long periods.

I would say the engineer/programmer made the choice that for cross-band you will only get half the power out of either side inline with TassieJay comment above. Keeping the total at the max for what one side could do. Maybe a better choice would be looking at power settings and adjusting the high side output up until the total is max for the radio specification if the electronics are built with that level of control.

Not may hams I know have taken a really close look at their cross-band setup. Usually there concerns, because of duty cycle are battery life (car installation) and heat addressing both by using the least amount of power that gets the job done. Are you getting the area/range coverage you are expecting? I'm not sure how the ht setting factors in or just a FYI data point in the overall setup.