Syntor X Experts

[Tim]

Hi Folks,

I picked up a couple of high band Syntor Xs today with
the cables and HHCHs.

As I don't need anymore highband radios (but looking for
some low band ones), I thought that I could replace the
highband drawer with a lowband one.

What kind of interface issues will I have between the two
drawers?

Is there a special board interface between the HHCH and
drawer, vs a 'real' control head? If so, can I swap it from
the high band drawer to the lowband?

I only need a couple of frequencies on 6 meters, so I can
handle the numeric display. (my wife also likes the fact
that there won't be <one more> control head in her car)!

Thanks,

Tim

[Mike B]

It mostly depends on if you have a radio drawer internal HLN4728 HHCH interface board that mounts above the personality board or an external SIU box HHCH interface:
http://www.onfreq.com/syntorx/hhch.html#hhchsiu

The personality board jumpers are different for HHCH and really different for the internal HLN4728 HHCH (two chips are also removed from the personality board).

The main personality board jumper difference is JU20 is installed for low band radios that have this jumper.
http://www.onfreq.com/syntorx/syntorx/j ... l#top_jump

Additional information on the personality board differences is here (for example the HLN4915A is purpose built for low band radios without any JU20 or L2):
http://www.onfreq.com/syntorx/syntorx/p ... ml#perinfo

One possibility is if both personality boards have a JU20 jumper, you could swap out the entire personality boards between Syntor X VHF HHCH and Low Band non-HHCH radios. If JU20 is missing from either board then you will have L2 inductor bypass configuration problems (only the low band should install JU20 and bypass L2). Make sure to test both VHF and Low Band radios first. There is no point to swapping dead components between radios.

If you give me more specific information (particularly the HHCH interface type and all the personality board part numbers) I can be more helpful.

[Tim]

Hi Mike,

Thanks for the info & links!

The High band x9000s that I have all have the internal HLN4728,
some are rev A, and some are rev F. They have the external
HHN4015 box, but I don't think there is anything inside but
but a couple of connectors.

As I haven't gotten any of the low band x9k rigs yet, I don't know what
they will be. It's good to know that I can 'make' the 4728 board work
with a non-HHCH rig. As I understand it, there is a programming option
in the module to specify a HHCH or regular head. (I'll have to find somebody
to program the modules, or get one of the specialty modules that can
be prog'd by a PC)

I'll peruse the links in more detail & if I have more questions that don't
sound too dumb, I'll drop you a note.

Thanks,

Tim

[Mike B]

I'm getting really confused by your new use of X 9000. There are 3 different major variations of conventional Syntor radios. The original Syntor, the Syntor X and the Syntor X 9000. These are all very different radios:
http://www.onfreq.com/syntorx/#modesc

The Syntor X 9000 has a completely different personality board that cannot possibly use the HLN4728. In fact the X 9000 only uses an external SIU box for the HHCH interface.

According to the factory manuals, the HHN4015 is a Securenet security housing for the YLN1056 SIU. The HKN4216 is supposed to be the correct non-Securenet cable junction box for the HLN4728 (Securenet versions use several different junctions - see the HHCH link bottom of the page). I suppose your radio may have come with the wrong cable accessories or maybe it is a working Frankenstein setup assembled from other radios? It will be critical to sort this out and get the HHCH working on their current VHF radios first, before you will know if they will be of any use on a low band Syntor X radio.

The Syntor X 9000 requires special HHCH RSS for use with the external YLN1120A SIU box. In fact the factory X 9000 HHCH is usually a dual radio setup with 01-06710T70 Dual Radio U501 chip Firmware (it can be implemented on a single radio):
http://www.onfreq.com/syntorx/syntorx9k ... #x9ksiucab

The Syntor X does not require any special software for the HHCH. There are some Syntor X HLN4728 configuration jumpers:
http://www.onfreq.com/syntorx/syntorx/j ... ml#xju4728
http://www.onfreq.com/syntorx/images/hln4728.gif

The available features you will be able to program into a Syntor X code plug depend on which switches are located on your version of the HHCH. See the HHCH link "Syntor X HHCH Model Numbers", for info on the HHCH versions. For example, if you do not have a scan switch on your HHCH version, programming the scan list feature into the code plug will not make much sense.

[Tim]

Mike - I just re-read my post, and understand why you are confused!!!

All of the HHCH stuff is with a Syntor X.

I've been doing some other deals with x9ks, and guess
I wasn't paying attention to what I was typing.

Sorry for the confusion.

Tim

[Tim]

Mike -

Are the HLN4915A/HLN4760 boards interchangeable between
series, or are there band specific components/software on the board.
i.e. VHF to Low Band

I have seen several software programs which will allow you to re-program
the "Code Plug" EEPROM. However, I have not seen any indications on those
programs that would specify a HHCH. Never having seen a 'suitcase programmer',
I don't know if there is an entry to specify an HHCH.

Are there schematics available for the 4915A or 4760A/B/C?

thanks,

Tim

[Mike B]

The VHF service manual revisions that cover different schematics are listed here:
http://www.onfreq.com/syntorx/syntorx/m ... ml#xvhfloc

The HLN4915A Personality Board documentation is found in the 68P80100W51-O low band manual and 68P81060E05-A VHF manual (it is special version of an HLN4760A with 2 parts changed):

http://www.onfreq.com/syntorx/syntorx/m ... html#xcman

The HLN4915A is missing L2 and is not recommended for use in a VHF radio. It is a low band only board. The 4760A works in VHF or UHF radios. The 4760B and 4760C will work in a Low Band, VHF or UHF radios.

There is no special programming entry or identification for the Syntor X HHCH. You simply program the radio code plug with "normal" features the HHCH control switches support. There is Syntor X code plug software (for IBM PCs) available if you do not have a suitcase, but have an EEPROM burner instead:
http://www.onfreq.com/syntorx/links.html#top_links
http://www.onfreq.com/syntorx/prom.html#top_prom

You could also post a request on the board asking who programs these nowadays.

[Tim]

Hi Mike,

I got the lowband Syntor X, and replaced the original control board with
a VHF control board that had the HHCH board attached. Reprogrammed
the plug, and it seems to work fine.

My only concern is the power out on 6 meters. I notice that is about 60
watts 'wide-open', whereas down at 29.6 it is about 90/100 watts.

I am looking at the PA, and it appears that the output filtering is on this
board. Should any tweaking of the filters be required to get full power
out on 6? Is there an easy way to do it? (It doesn't look like a fun task to
remove the PA's PCB from the casting & remove the shields). Perhaps
replacing of some of the filter caps that aren't under shields may work.

The receive sensitivity is very good.

Thanks,

Tim

[Mike B]

These radios were designed for up to 50 MHz service. Back in the old before cable days, TV channel 2 over the air reception was rather close to 50 MHz, so it made sense to make the harmonic filter on the Power Amplifier (PA) deck have a sharp cutoff frequency to avoid TV interference. First you need to test your radio within the original factory frequency range (within 31 to 50 MHz) on a good dummy load and accurately measure the power output. A good dummy load will ensure a consistent 50 ohm load no matter what frequency is used. These radios will fold back the output power if the antenna connection impedance is not matched. Make sure your coax is good, really old or damaged coax connected to a power meter and dummy load will cause problems. If your radio is working correctly within factory specifications, then try going down to 29 MHz and up to 53 Mhz to measure the Tx power. You should be getting more than 60 watts, at least that has been my experience with these radios on a good test setup. I have been able to get my Syntor X low band radios to put out more than 100 watts within the factory range even though I do not run them above that.

If your radio is found to be working correctly changing the cutoff frequency will not be simple or easy. You do not want to cause spurious emissions or impedance mismatches. I have never found it to be enough of a problem to warrant any changes, but I never had a radio drop all the way down to 60 watts on a good test setup.

[Tim]

Hi Mike,

Did some measurements with known good feed line/wattmeter & dummy load.

At 50.0 mHz, the power out was 48W @ 13.7 A
At 29.6 mHz, the power out was 72W @ 20.2 A

When testing at 29.6, after holding the mic down for
15 seconds, the metal strap on the PA (1/4" x 2.8") got
really hot.

After examining the PA, I noticed that on the base of
the final transistor closest to the driver that the
inductor was not soldered to the base lead. It didn't
look like it ever had been soldered. Although, it didn't
seem to make any difference in output power when
reconnected.

Perhaps there's something amiss in the PA, as the input
currents don't really seem right with the output power.

Tim