Noise, Noise and more Noise – Adventures in Repeater Filtering

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Like a lot of radio groups, we jumped on the opportunity for an inexpensive, modern repeater to upgrade our older crystal controller GE Mastr II and Motorola MSR2000 commercial base stations. Yaesu offered what seemed like a deal too good to be true: $400 refurbished dual band, analog/digital repeater with a 3 year warranty – shipped no less! We jumped on them with plans to replace our VHF and UHF repeaters on the mountain and UHF repeater in the valley. After roughly 2 years of prep work, we deployed the mountain top repeaters in October 2019 to much fanfare.

Couple things we noticed immediately as we deployed the units –

  • The squelch pot had to be turned up almost half way on the repeaters to clear the COS light on the controller. On the bench in the valley, these only needed a single notch on the squelch which resulted in 0.22 uV sensitivity for 12 dB SINAD on a borrowed HP service monitor.
  • There was noticeable whine from the cooling fan on the receiver after the first key up.
  • Coverage on the VHF side had dropped by about 30 miles on mobile and 40 miles on handheld.
  • UHF talk out range had dropped by two thirds.

So we stepped back and looked at the spec sheets, our installation and considered the possible issues.

  • Yaesu’s DR-1X was only rated for 20 watts for continuous duty; these replaced 100 watt repeaters.
  • Yaesu’s selectivity spec is only 55 dB; the repeaters they replaced were north of 90 dB.
  • We had added the OCI BPF (preselector) in line with the antenna on the UHF repeater but inline with the receiver chain on the VHF.
  • The fan noise was not present when using the internal controller.

Several emails, phone calls and IMs with other repeater owners, tech support and elmers results in a common theme – our expectations for a $400 repeater to replace commercial hardware might have been too high to start with.

I visited the site in mid November for some deeper testing and reconfiguration. The selectivity issue was rearing its ugly head as the site noise floor was nearly -55 dBm! Our Mastr II and MSR2000 had been rock solid in this environment for over a decade with excellent low power handheld coverage in the valley and fringe mobile coverage out beyond 60 miles. Something had to change.

For reference, our mountain site is:

  • 2200′ HAAT
  • Colocates with UHF SCADA, UHF DTV x12, FM 150 watt broadcaster, wireless ISP microwave, 4 cell carriers and 7 carrier microwave links.
  • Is within 2 miles of VHF/UHF/700 LMR repeaters x24
  • Is within 5 miles of FM broadcast x15, VHF DTV x3, UHF DTV x6
  • Is within 6 miles of several other amateur repeaters
  • All within line of sight of our antenna

With a borrowed spectrum analyzer, I began methodically testing the noise floor at the repeater sub bands, in the FM broadcast band, and in VHF & UHF TV broadcast bands. Not all of the screenshots saved but you can see the changes below. The equipment used in line with filtering:

VHF – Sinclair Q2220E BpBr Duplexer > OCI 2m BPF > Mastr II Front End/Preamp Helical Filter

UHF – DB Product DB-4071-WA BpBr Duplexer > OCI 70 cM BPF > Mastr II Front End /Preamp Helical Filter

Excuse the mess while testing Mastr II Helical Filter assemblies

Why add helical filters? If we wanted commercial performance out of our amateur repeaters, why not put commercial front ends ahead of the receivers. For the most part, it had the desired effect, with a 10-12 dB difference in effective noise floor at the receiver port of the repeater. Why the preamp? The helical is very lossy (north of 12 dB) when tuned. We used the Mastr II 12 dB preamp which we’ve had in all of our repeaters over the years as it is a moderate gain preamp with decent noise factor and fits in the front end casting, resulting in +1 dB gain for the VHF and -1 dB loss for the UHF assembly.

Before we get to the SA shots – a summary:

  • Yaesu DR-1X repeaters are a great value at a quiet site or for portable tactical use; it struggles in high RF environments
  • BpBr duplexers can have mixed results for out of band noise suppression, but for the most part, will require some form of preselector and additional filtering when in high RF environments
    • The VHF duplexer only presented 2 dB isolation in the FM broadcast band compared to the input
  • Interfacing to an external controller took a lot more effort and time than we anticipated, delaying our deployment by over a month
  • With the snow coming soon, we will be regrouping over the winter to determine our next steps, however, we will likely move the DR-1X to our valley sites and deploy commercial hardware at the mountain
  • The support we’ve received from the amateur community and Yaesu tech support is top notch
  • Not every solution works every time

Screen shots from Viavi ONX-630 running 3.16.10 firmware.

Download the full resolution screenshots here:

146.780-/444.725+ Repeater Update 10/22/2019

Good day all, an update on the upgrade of our Wilderness Repeaters (aka North Command (146.780) and North Operations (444.725). The goal being to replace the aging and damaged equipment thus allowing a more efficient operation and much better handheld coverage through the valley.

On October 20th, a team of five Valley Wide REACT members (AJ K6LOR, Russ N7SMA, Chris N3JHR, Tim N7UBO, and myself Tyler K7XTS) took a trip up to the site to begin upgrade work on the repeaters.

So here is a look at our old repeaters or a before upgrade. Pre-upgrade it was found that the 444.725+ GE MASTR II had an issue that as it began to warm up after a few minutes it would lose just about all of its receive capability. It has not yet been determined what the cause of the issue is yet but we’re assuming old age.

Here is a look of the antennas at the current time. The plan was to remove the top antenna (146.780) and replace it with our new custom made Sinclair folded dipole dual band antenna. Unfortunately due to an unknown factor of a new antenna lower on the pole we were not able to gain access to the top of the pole to add the new antenna. So that is on hold until next Spring at the moment. If you look just to the left we were able to mount the new antenna to a lower spot on the building for a temporary solution.

Here is a closer look at the new antenna just after receiving it, the black blocks are just from shipping.
Here we see Chris N3JHR mounting the nearly 18foot long antenna in the temporary location.
Chris N3JHR (ground) and Tyler K7XTS (ladder) finishing antenna tests and connections.
Here we see Tim N7UBO sealing up some of the new half inch heliax coax runs.

New Repeaters!

So you’ve seen the antennas and antenna work, now lets get to the good stuff!

Below you’ll see a look at the new repeaters painstakingly set up and modified by the team lead AJ K6LOR. Two Yaesu DR-1X Repeaters, one is for the 146.780- and the other is for the 444.725+. Below that is the UHF duplexer for the 444.725+ and to the left outside the rack is the VHF duplexer for the 146.780-. And finally at the bottom of the rack is the Arcom RC210 Repeater Controller. It is estimated that will the loss of filtering and what not that the 146.780- is outputting 20 watts of power and the 444.725+ is outputting 26watts of power.

So status of the repeater modes of operation. At times the repeaters may be set to fixed analog use when required for resource use as needed such as event use. At this time we also do not have access to internet at the site, so there is no YSF rooms or internet linking.

Repeater Controller

Speaking of linking, the 146.780 and 444.725 do have a full time link to each other unless it is decided that they need to be unlinked for different resource uses.

As for other controller modes and what not, It may be in the works that the repeater will have a special event mode for use with various events thus eliminating voice ID, courtesy tones, and shortening hang times. As a REACT member you will be notified once modes will have gone into effect. If you are not involved with an event once the repeaters go into event mode it is asked that only event and emergency related traffic be passed via the repeater.

Also now the repeaters broadcast a PL tone of 100hz to help prevent squelch crashes and what not but that is still being worked on. It is worth noting that on the 146.780 repeater if you set up a receive tone of 100hz you may not hear the repeater ID, this was done intentionally to help cut down on user radio traffic.

It is also important to note that at this time repeater controller fine tuning is still taking place so repeaters modes or timings may be changed without notice.

Future Plans

AJ K6LOR is still working with fine tuning the controller for our needs. As for other physical work will have to wait till summer of 2020 such as moving the antenna to the higher proper location shown in the pictures above. At this time, it is uncertain but it may be possible to add a VHF power amplifier to the 146.780 and weather radio alerting down the line.

Summary

For the time being, we have achieved our greater goal of replacing the old equipment with new equipment and it appears that handheld coverage and coverage in general has greatly improved.

Well that is all for the time being, however we will do our best to keep you informed of future upgrades of the repeaters including our Valley Ops and West Ops repeaters. If you have any questions or concerns please shoot us an email at info@vwreact.org or you can come check us out our meeting the 3rd Wednesday of every month at the Nampa IHOP on Caldwell Blvd. at 7 pm MST.

We want to give a thanks to all who were involved in the upgrade project, and a big thanks to AJ K6LOR as he took and is still taking big chunks out of his busy schedule to help keep our repeaters humming along.

73’s and see you next time, Tyler K7XTS signing off.

Beautiful view of the Treasure Valley from the repeater site.

Willow Creek Boy Scout Invitational – Special Event Station W7C

The special event station W7C will be operated April 14, 2018 at the Willow Creek Boy Scout Invitational Camp, 14 miles north of Emmett, Idaho on the west side of Squaw Butte or approximately 35 miles northwest of Boise, Idaho.

Operated by Hoot Gibson, KB7RBX, this HF and VHF special event station will demonstrate Amateur Radio to over 300 Boy Scouts, Venturers, Webelos, Cub Scouts and Civil Air Patrol Cadets as part of a demonstration area including Civil War Reenactors, Smokejumpers from the McCall USFS base, a blacksmith and much more.

The demo area is one of 10 stations the participants rotate through on Saturday as part of the competition, which also includes fire building, Scout knowledge, marksmanship, first aid, flag etiquette and more.

To receive a special event QSL certificate confirming your contact with station W7C, please send a letter sized self addressed stamped envelope (SASE) to the communications coordinator:

AJ Grantham, K6LOR

W7C Special Event Station

583 Valley Street

Middleton, Idaho 83644 USA

New updated DMR Codeplugs

I’ve updated the Boise DMR MotoTRBO codeplugs for popular radios and fixed a zone naming issue. Old codeplugs have been moved in to the Old Codeplugs folder.

Right click to save as – these are NOT working in Microsoft Edge browser for some reason.

Connect Systems CS750

Tytera/TYT MD380 (may work with MD380G/MD390 versions as well – just copy and paste)

Motorola XPR4550 mobile

Motorola XPR6550 handheld

Also available is the 450-512 MHz split to Amateur conversion file in case you have a high split radio. READING the radio with this codeplug will reset it back to the factory split – just write and save, using the saved file moving forward.

Motorola XPR6550 450-512 modified codeplug for Amateur Use

73 all,

AJ, K6LOR

Just in time for the holidays! New Brand Meister Boise DMR Codeplugs

OOPS! We forgot to update the CS750 link – it’s correct now! -AJ, K6LOR

 

We’ve updated the codeplugs for the Boise WA7GSK DMR repeater just in time for Christmas!

Right click and save as on the links below:

Connect Systems CS750

Tytera/TYT MD-380 (import will work for MD-390 as well)

Motorola MotoTRBO XPR4550 mobile

Motorola MotoTRBO XPR6550 handheld

As always, make sure you CHANGE YOUR SUBSCRIBER ID before you get on the air! You can get your very own sub ID from DMR-MARC here.

Happy Holidays and 73 from AJ, K6LOR and the group at Valley Wide REACT!

Posted in DMR

Boise, Idaho DMR/MotoTRBO Amateur Repeater Codeplugs!

Boise’s DMR repeater has been busy with chatter the last few days since it came back online. Thanks again to Al, WA7GSK, Fred KE7FIX and the group at Gem State Communications for bringing it back on to the DMR MARC network!

Connect Systems has brought down the price on the MD380 UHF handheld clear down to $110! Incredible value to get on digital voice and talk to the world. As I write this post, I’m QSOing with a station in Nova Scotia and New Zealand 🙂 You can buy an MD380 here.

Want to know more about DMR aka MotoTRBO in Idaho? Here are a couple short articles and the DMR Primer:

Amateur’s Guide to DMR

DMR in the UK

DMR at the Windsor, Canada Field Day

Motorola Amateur Radio Club (DMR-MARC)

I’ve built sample codeplugs for the following radios:

Motorola XPR4550 UHF Mobile
Motorola XPR6550 UHF Handheld
Connect Systems CS750 UHF Handheld
TYT/Tytera MD380 UHF Handheld

All that needs changed is the subscriber ID to match the one you have requested from DMR-MARC here:
Request your radio subscriber ID from DMR MARC

The radio IDs have been defaulted to “1” in each codeplug and will need to be changed prior to accessing the network.

Right click to save as:
Connect Systems CS750 Boise Sample Codeplug (entire DMR-MARC contacts database)
Tytera/TYT MD380 Boise Sample Codeplug
Motorola XPR4550 Boise Sample Codeplug 403-470 Split
Motorola XPR6550 Boise Sample Codeplug 450-512 Split hex edited down to 430 MHz (write to radio, reading from radio will return to original 450-512 bandsplit)

Software used:
MotoTRBO CPS version 10.7 with wideband patch from the gents at Communications.support (patch here)
Connect Systems CPS HAM2000 version R4.00.13
Tytera MD_380 Radio Programming Software V1.30.0

Watch the C-Bridge live here!

Interested in more info? Email me directly at k6lor AT vwreact DOT org or catch me on the 444.075+ DMR repeater on Local Color Code 1 Timeslot 2 Talkgroup 2 🙂 I’m also typically monitoring the 146.780-/444.725+ repeater network.

Welcome to 2015

Happy New Year! It’s going to be a very busy year for VWR. Your help is needed to make the events we support go smoothly. Volunteer now!

On the topic of repeaters, DMR aka MotoTRBO had a very big year in 2014, with 3 times as many active repeaters on DMR-MARC as there were in 2013. We are working together to find the best solution that will serve the community.

If you are interested in DMR aka MotoTRBO, please contact me at aj.grantham at gmail dot com!

Brief website outage & Fit One 2014

Sorry for the downtime everyone! The domain name that this site’s DNS points to expired a couple days ago and I thought it was set up to automatically renew. Oddly enough it wasn’t. So when it expired, the private NS entries dropped out and hosed several other sites. We’re back up!

Major thanks to everyone that came out this morning to assist on Fit One 2014 put on by the folks at St Luke’s. No major issues and things ran pretty smoothly. This year the organizers were on DMR rental radios (Motorola MotoTRBO XPR6550s) so we were only able to communicate with them using the one spare radio they had. In years past they’ve been on analog narrowband UHF that we were able to communicate directly with. Major improvement over last year as logistics was on simplex and medical was on the only repeater. This year both medical and logistics were on the repeater (different timeslots).

Quick edit – handhelds used were XPR6550s, not the mobile XPR4550 🙂