Saber Out of Band Question

[fogster]

I've got an H43QXK7139CN Saber with an H33 codeplug. The original H43 codeplug was on the 136-151 split. The H33, as you probably know, is 146-174 or the like.

To test the radio, I put in 154.57, my favorite MURS frequency. I keyed up and got the sidetone (for PTT-ID), but the TX LED did not illuminated. The sidetone dropped after the programmed 300ms, but then emitted a constant 'alert' tone, like the one I get when trying to transmit on a receive-only channel. Receive is also completely deaf. (My thought at the time: I'm too far out of band.)

However, I threw in 146.520, which falls into both the 'hardware' 136-151 split and the H33's split. Should work, right? I got the 'clear beep,' during which the TX LED did illuminate. (This channel does not use MDC, so no sidetone.) After that, though, just the same continuous error beep. Listening on a scanner, the squelch never broke. (I haven't tested receive here yet.)

BUT, when I put the original H43 (136-151) codeplug back in, 146.520 worked just fine. So now I'm confused: why does a frequency within both the hardware and software (model-number imposed) splits only work on one model number and not the other?

[FireCpt809]

sounds like the VFO was out of lock. The modules are set up for the low split and wont go more than 1-2Mhz out of band. If its a low split and you want to go in the 154 mhz you will have to change out the modules to a mid split to get that range

[Microwave Mike]

Well the short answer is YES.
When the Tx light does not come on when transmitting means that the Tx VCO is not in lock and working. I believe that the tone in recieve means that the Rx VCO is also not in lock.
Each band split for the hardware and software side need to match.

Now there was a version of Saber RSS that did let you program a radio
plus 10 Mhz and minus 5 Mhz of the band split. It was for use in countries outside the US.

Hope this helps

mm

[fogster]

I'm still confused, though. 146.52 isn't out of band either way.

And isn't the receiver the same across all VHF splits?

[K4RUR]

Hi,
When you put the 146-172 codeplug, it makes the VCO unlock. The modules do not go very far out as was stated earlier. When you change the bandsplit it shifts the internal freq also and the lower split modules will NOT work, believe me, I tried to get it to work too and NADA.


Good luck,
Lowry K4RUR

[AEC]

What is the synthesizer's model number?

NLE8201x or NLD8210x?

If it is the NLD8201, and you programmed it as a 146-162 band split, that's the problem, the NLD8201 will not operate in that band split, you will need the NLD8210 synthesizer.

Check U5, the 5-pole filter, the best one for use in the ham and commercial band will be the NFD6092 as it is designed to cover 146-174 Mhz, where the NFD6091 is for the 136-151 Mhz. band split

Same goes for the 2-pole filter and the FDS, they should all be in the same band split for proper operation, as well as the PA(NLD8773).

[fogster]

I ended up swapping out the synthesizer, the PA, the FDS, and the 2-pole filter. Works like a charm now. (Where's the five-pole filter? All I can see in the radio after removing said modules is the receiver, reference oscillator, and the secure bypass module.)

BTW, thanks everyone for the help.

[AEC]

The 5-pole filter is located UNDER the VCO.

It's the gold colored 'module' that is retained with two fingers on the VCO case, as you have to spread the fingers apart and gently lift the filter out of the VCO body, there will be a black rubber pad on the bottom, if you see that, you are looking at the 5-pole filter.

Be careful, those fingers are necessary fo the radio to function as they are RF connections.

Once you remove the filter, there is a red rubber isolation pad on top, and if you remove this, you will see the filter's model number printed on top.

IE: NFD6091x OR NFD6092x for the VHF models.

The UHF models are similar as to filter placement, but are of a different design as well.

[fogster]

Edit: The issue I mention in this post has been fixed.

Okay, perhaps I'm doing something wrong. I found the 5-pole filter, and swapped them between my low-split and high-split. (I thought the thing they were underneath was the receiver module, though. Should I have swapped out the whole module, rather than just the 5-pole filter?)

The audio is now very high-pitched. I hit the monitor button to open the squelch, and get a very high-pitched rush of static. Attempting to transmit now gives me a very high-pitched beep (actually, a very quick beep, then a continuous beep... the first might be the clear beep?), more the frequency of a home smoke detector than the usual error beep. I'm by no means an audiophile, but I'm going to guess it's twice the normal pitch.

What the heck did I screw up?

[fogster]

I wasn't too clear in that reply: the radio will also not transmit, even on frequencies it did before I swapped these modules out. All the modules fit back into place nicely.

[fogster]

Heh, fixed.

For the record, putting a reference oscillator into a Saber upside down apparently causes all noises in the radio to be higher-pitched. (Along with the obvious problem of causing it to neither transmit nor receive.)

[AEC]

Heh, fixed.

For the record, putting a reference oscillator into a Saber upside down apparently causes all noises in the radio to be higher-pitched. (Along with the obvious problem of causing it to neither transmit nor receive.)

You got 'lucky' with the reference oscillator swap, most of the time, they just plain will not turn on and show anything in the LCD.

As I noted to another here, the easiest way to tell is to look at how the squared section(notch) is aligned in the radio.

The reference oscillator is round on three corners and squared on the fourth, this is pin #1 and MUST be inserted properly for the radio to function.

Standard Saber: the square 'notch' faces the top of the radio

Systems Sabers: The squared 'notch' faces the bottom of the radio.

U4 and U5 are a complete assembly, with U5 being the 5-pole filter mounted to the underside of the VCO(receiver) module(U4).

Since all of these modules are designed to cover the entire UHF and VHF spectrum, only the filter underneath is necessary to replace if you intend to operate the radio above 151.00 Mhz. so the receiver does not suffer degradation.

Same goes for ALL frequency sensitive devices in the radio, namely the 2-pole and FDS and P.A.

The NLD8201x covers out of band only to a point, then forget its use, you will have to use the NLD8210x to get above 160 Mhz. and below 145 Mhz.

With the proper modules installed and the radio tuned correctly, there is no reason any Saber should not be able to be used from the low end of 2 Meters all the way up to at least 169.000 Mhz. without any trouble whatsoever, all of mine do this with ease, and yours should as well.

The UHF models are a little different, but I can easily get to and use 475.9875 without a problem, and with good sensitivity as well.

While the UHF models are a little more troublesome, the VHF models are a snap to get working where you need them to.

[DJP126]

U4 and U5 are a complete assembly, with U5 being the 5-pole filter mounted to the underside of the VCO(receiver) module(U4).

Not to pick a nit but U4 is NOT the VCO. The VCO is U300 (also known as the synthesizer). U4 is the RF amp/1st mixer/crystal filter portion of the receiver.

[AEC]

I saw the mistake but did not correct it.

The rest of the information is correct though.