Mid Block to Uniden

[NightProwler]

I have just finished putting the mid block into an Audioline 340 using the following website...http://www.m0ysu.com/audiolinemidblock.html

The UKFM works as it should and the mid block is receiving perfectly but output power is zero. Any ideas dudes?

Cheers...Rich

[Buick Mackane]

I have just finished putting the mid block into an Audioline 340 using the following website...http://www.m0ysu.com/audiolinemidblock.html

The UKFM works as it should and the mid block is receiving perfectly but output power is zero. Any ideas dudes?

Cheers...Rich

Yeah, Even out the power

[NightProwler]

Tried that but on the watt meter it's reading zero and the needle on the radio don't move at all. My Cobra with the Sirio plugged into it picks it up on about signal 3

[normal]

So it transmits on channels 1 to 40 on UK band but not at all on mid band?

I could be wrong but I think that set of instructions is missing a step.

Pin 4 on the PLL chip is used to disable transmission if the PLL is out of lock.
People usually prevent that feature from working when doing a mid
conversion so the rig will still transmitt but on the wrong frequency
if the PLL is out of lock, eg if the VCO dosn't go down far enough
it might transmit some power with channels 1-20 mid selected but actually be putting
out an unstable carrier somewhere around channel 20 mid.

If you leave the lock detect from the UK chip controlling the TX inhibit then
the rig won't transmit on mid band.

I suspect that what you need to do is cut the pcb track going to pin 4 and
connect the track (not the pin) to the 8volt supply.
Try it at your own risk.

I'd do a couple of checks
a) Measure the voltage on pin 4 on the midband chip. If it's around 0.7volt
with UK band selected and 7volts on channel 40 mid then the PLL is locking,
at least on 40mid.

b)measure the VCO tuning voltage. It needs to be within somthing like
1 to 6.5 volts and should change in small steps as you click up the channels.

The VCO needs to run slightly lower on receive than on transmit so if
it receives ok on 1 mid the PLL should lock for transmit down to 1 mid as well.

Oh hang on, Black spirit already covered this a few months ago click here

[NightProwler]

It's transmitting on every channel on each block and receiving perfectly, I can hear myself coming through my Cobra which is sat next to it, Audio is clear but the signal is weak and nothing shows on the watt meter, Not even an SWR reading. By the way this is the first time I have done this

[normal]

That is consistent with the disable-tx-when-the-pll-is-unlocked feature still being active from the UK PLL.

[bigpimp347]

Oh hang on, Black spirit already covered this a few months ago click here

Ooops link is for a Ranger 3500 fault

saying all this i did a Mid to UK40 on a 400..
still don't pigging work..!!

maybe i should have checked the rig before hand.

[163TM847]

Yep one vital instruction is missing and i also emailed him to inform him of this, He replied but never updated it.

You will also need to bridge a capacitor to improve the output across the two bands.

S7001145.JPG

[NightProwler]

Thanks Nick I'll try it now and let you know

[NightProwler]

Nick you are the man Now works perfectly.

[bigpimp347]

Yep one vital instruction is missing and i also emailed him to inform him of this, He replied but never updated it.

You will also need to bridge a capacitor to improve the output across the two bands.

S7001145.JPG

is this the same with the 400 ??

[Buick Mackane]

Yep one vital instruction is missing and i also emailed him to inform him of this, He replied but never updated it.

You will also need to bridge a capacitor to improve the output across the two bands.

Good bit of info nick

I see from that pic the lock detector has been cut and another voltage fed in to the TX circuit,

I wonder how many people have done this mod using instructions from that site only to be left scratching their heads when it didnt work

Anyway glad you got it working rich

[NightProwler]

Yep I now have a nice little 80 channel Audioline, I have no idea what I will do with it tho. The only question left is, What the hell would we do without Nick?

[Buick Mackane]

What the hell would we do without Nick?

Well its a little know fact that i PM nick all the info and he posts it on the forum, I dont like the publicity

[bigpimp347]

What the hell would we do without Nick?

Well its a little know fact that i PM nick all the info and he posts it on the forum, I dont like the publicity

Joined: 21 Aug 2012, 18:30
you must be an old banned member in disguise then