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St Petersburg Repeaters are ONLINE!

Florida Simulcast Group is pleased to announce three new repeaters on the air in downtown St. Petersburg.  Our repeaters are located at the 400′ (121m) level, and should service most of southern Pinellas county for portable users.  These are linked full-time to our repeaters in Tampa and other systems depending on the mode.

Based on early testing we are seeing solid coverage of downtown and the beaches.

The frequencies are:
443.7625 NXDN (RAN1)
444.3750 Analog and P25 (146.2 PL/293 NAC) and Allstar Node 44233
444.9625 DMR (CC1)
All the above have a +5 MHz offset.

For more programming info on the digital modes visit

Having three repeaters work well on a single antenna was no easy task.  FSG had to employ extensive filtering, branching and combining to enable all repeaters to operate without causing self interference.  A gallery of our testing and combining may be found online here, and a reddit thread describing the build is here

A short video tour is available on YouTube.

All repeaters make use of HamWAN for linking to other sites and beyond.

These are open for all amateurs to use and testing is encouraged.

Our deployment of HamWAN, a multi-megabit internet connected network over Ham frequencies, is now live in Tampa.

With a proper CPE setup you can expect to get 10-20 MBit/s TCP throughput to your network.  We support both IPv4 and IPv6 address space.  Anyone who’s licensed (Tech or higher) can get on 5.9 GHz with equipment for under $200-250 dollars.  This is perfect for linking repeaters and other critical points to the internet for redundant radio linking and high speed redundant IP data.  Leave your TNC at home and experience what packet radio should have been.

Below is a coverage map showing a 30 ft client radio elevation (and clear line of sight) to our site in Tampa.  This is an estimate for minimum signal (-75 dBm), as such if you’re marginal it may not work as well, even though the radios will work down to -90 dBm.

-75 dBm or better 30' client

-75 dBm or better 30′ client

Attached is a coverage map you can overlay into Google earth and explore.

To get online please subscribe to our FSG mailing list and we can get you authorized and your client radio configured for our access points.  We have a few test radios available if you want to test a site out before committing to it.



Repeaters are online!

We now have the 220, 440 and 900 MHz repeaters online from high up in downtown Tampa.

The 444.575 test repeater has been removed.

224.280 -1.6 MHz and a 146.2 PL tone
This has been tested out to about a 50 mile radius from a 25W mobile.  HT coverage is solid out to 15 miles and we have numerious reports of people running .3 to 1 watt HT’s from this distance.

443.525 +5 MHz and 146.2 PL and P25 NAC of 293

927.050 -25 MHz with DCS 546 and P25 NAC of 293.
900 MHz is narrowband FM, and we are investigating turning on “hearclear” companding.

All transmit PL and will respond to reverse burst if your radio is so equipped.

As of now none are linked as we are working on internet access at the site.
All these are open access, you don’t need to be a member of FSG to use them.

UHF Test repeater is online!

444.575 is now online from high up in downtown Tampa!  It requires a PL of 146.2 Hz.  P25 is supported with a NAC of 293.

Thanks to the hard work of our members we were able to bring this online over the weekend.  It is a “Proof-of-Concept” repeater designed to cover downtown Tampa and the central business district buildings.  This necessitated a lower gain antenna for solid coverage below the site and in the surrounding ground level.

The repeater consists of the following:

  • 25W Motorola Quantar
  • DB-404 Antenna
  • Mobile notch duplexer
  • DB-404 antenna
  • 3/8″ feedline (2.3 dB loss)

We plan to change out the feedline to a higher quality Heliax cable which should improve the receiver.

Below is a projected coverage area of the repeater to a HT at 5W.  We’ve had good mobile reports much further than this shows.  Please try it out and report back on our mailing list.

Test repeater 25W DB-404 2.3db feedline loss to 5W HT unity gain coverage
Projected HT coverage into the repeater


Below are some pictures of the repeater site after we got done.

Byron K4SIP and DB-404 antenna

Byron K4SIP and DB-404 antenna

DB-404 on Roof Looking down to the Port Quantar installed in rack Quantar online Sunset over Tampa Sunset to I4 Telewave 220 Antenna




We’re 501(c)3 approved

Our IRS form 1023 was approved by the IRS, however they keyed our address in wrong to their systems.  Thus we do not have a copy of the determination letter.  Further complicating this the IRS will not resend us a copy to our correct address.  They are demanding we submit a change of address form and a letter to them…

I’m submitting a form to the IRS later today and expect to have our address and a proper copy of the 501(c)3 determination letter on our disclosures page shortly.

Bryan W9CR

224.280 repeater progress

Much progress has been made on building the main 224.280 MHz repeater.

The rack mount case has been constructed and fixed to the Hamtronics modules, and the GPSDO master 10mhz clock source has been integrated with the units.  This consists of a PIC 16f88 micro-controller running code that will spit out the appropriate bits to the CPU as it goes into transmit.



The first revision of this code simply would power up, program the PLL IC and then shut down (no CPU noise).  This worked but it had the effect of running the PLL VCO at 224.280 all the time transmitting a low level (-24dBm) signal at all times.  This is enough to open the squelch of a radio about 2 blocks away.

We solved this by making the PLL move off frequency when not keyed.  When the repeater keys up, it now moves onto frequency in about 10ms and works flawlessly.


The other major issue was microphonics due to the cheap chip caps used in the VCO circuit of the hamtronics exciter.  Cheap ceramic capacitors can be piezoelectric, and vibrations will cause them to vary (very slightly) in capacitance.   A simple taping on the box will cause the frequency to swing 10-20 khz, which is unacceptable.  The suspect capacitors were changed to mica insulated units which do not have such a problem.

Between this and the potting of the VCO coil, almost all microphonics have been eliminated from the hamtronics exciter.  A stiff rapping on the enclosure now only varies the frequency a few Hz.

Hamtronics chip caps