Comparison

SJ705M vs RF Engineer Toolkit

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

SJ705M

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Support. 1. You can measure by connecting SJ705M. 2. Measured data can be extracted or shared as a file.

About

RF Engineer Toolkit

This app provides a comprehensive suite of 45 RF and antenna calculators for engineers and technicians. It offers unit-tested formulas for field, site, and lab calculations, including RF exposure and impedance matching. A free version offers 16 calculators, with Pro unlocking all features and advanced options.

Highlights
  • 45 RF and antenna calculators
  • Unit-tested formulas against industry standards
  • Field and site calculations (VSWR, link budget, RF exposure)
  • Design and lab calculations (Smith chart, impedance matching, filters)
  • Everyday RF conversions (dBm, W, V)
  • Free version with 16 calculators
  • Pro version with full access and advanced features
Features
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RF Engineer Toolkit is the calculator set RF engineers, tower and DAS technicians, PCB designers, and radio amateurs reach for every day. 45 calculators, every formula unit-tested against Pozar, Balanis, ICNIRP 2020, FCC OET-65, and manufacturer cable data — with live results, locale-aware input, and no ads. FIELD AND SITE • VSWR, return loss, reflection coefficient, and mismatch loss from any one value or a wattmeter reading. • Cable loss with manufacturer coefficients (LMR, RG, Heliax, 9913), SWR loss, and ERP. • Link budget with FSPL, cable losses, gains, sensitivity, and margin. • Antenna downtilt and coverage, radio horizon, Fresnel zone with earth bulge and clearance. • RF exposure against FCC and ICNIRP limits, with safe distance for public and occupational exposure. • Antenna separation and co-site isolation, including required spacing. • Dipole, helical, and parabolic dish design, near-field boundaries, and Doppler shift. DESIGN AND LAB • Smith chart with series and shunt elements, lines and stubs, exportable as an image. • Impedance matching networks (L, Pi, T) with Q and bandwidth. • Attenuators (Pi, Tee, bridged-T, L-pad) with E24 and E96 values and real achieved attenuation. • LC filter designer: Butterworth and Chebyshev, low-pass, high-pass, band-pass, and band-stop. • Receiver chain: cascaded gain, noise figure, IP3, noise floor, and SFDR. • Amplifier linearity: P1dB, IP3, back-off, IM3, and PAE. • Microstrip, stripline, coplanar, and differential-pair impedance with synthesis and substrate presets. • Coax impedance, cable delay and phase, quarter-wave transformers, and skin depth. • Power dividers and directional couplers, S-parameter conversion, and intermodulation products. • Rectangular and circular waveguides with WR tables, cutoff, and guide wavelength. EVERYDAY CALCULATORS • dBm, dBW, W, V, dBV, dBµV, dBu, and dBi/dBd conversion. • Wavelength, reactance, resonance, time constants, Ohm's law, dividers, series and parallel circuits. FREE AND PRO 16 calculators are free, and every Pro calculator can be previewed. RF Toolkit Pro unlocks: • All 45 RF calculators. • Searchable calculation history with saved inputs. • PDF exports of calculation result sheets. • Custom cable and substrate libraries. Choose the plan that works for you: • Yearly subscription with a 7-day free trial. • Monthly subscription. • One-time lifetime purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the current period ends. You can manage subscriptions in your Apple Account settings. PRIVACY No accounts. No analytics. No ads. No tracking. Your calculation history stays on your device. Privacy Policy: https://zhsystems.me/privacy-rf-engineer-toolkit-privacy-policy-terms-of-use/ Terms of Use: https://zhsystems.me/turms-rf-engineer-toolkit-terms-of-use/

Screenshots

SJ705M4 screens
RF Engineer Toolkit4 screens

Verdict

The call

The clearest difference is in-app purchases: SJ705M at none against RF Engineer Toolkit's 3. SJ705M also leads on iOS requirement (14.0 vs 17.6). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. RF Engineer Toolkit sells 3 in-app purchases, starting at $0.99 per month. SJ705M asks for nothing beyond the download.

Scorecard2 real differences · 8 level
SJ705M versus RF Engineer Toolkit: the parameters behind the verdict, then further details
ParameterSJ705MRF Engineer Toolkit
PriceFreeFree
Rating—5.0 (1 ratings) — better
Positive reviews—0.0% of reviews
Number of ratings—1 — better
Update frequency—Every 2 months
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS14.0 — better17.6
Further details — not scored
Size6 MB12 MB
Age rating4+4+
DeveloperYOHAN KIMVladislav Zhirnov

In-app purchases

None

SJ705M

No in-app purchases

3 purchases

RF Engineer Toolkit

Subscriptions2
  • Full version / monthly$0.991 Month
  • Full version / year$4.991 Year
One-time1
  • Remove ADS$9.99

Questions

Is SJ705M free?
SJ705M is free to download, with no in-app purchases.
Is RF Engineer Toolkit free?
RF Engineer Toolkit is free to download, with in-app purchases available.
Do SJ705M or RF Engineer Toolkit have ads?
Neither SJ705M nor RF Engineer Toolkit shows ads.

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